Bumps [meta](https://github.com/dart-lang/sdk/tree/main/pkg) from 1.11.0
to 1.12.0.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a
href="https://github.com/dart-lang/sdk/blob/main/CHANGELOG.md">meta's
changelog</a>.</em></p>
<blockquote>
<h2>1.12.0 - 2015-08-31</h2>
<h3>Language changes</h3>
<ul>
<li>Null-aware operators
<ul>
<li><code>??</code>: if null operator. <code>expr1 ?? expr2</code>
evaluates to <code>expr1</code> if not <code>null</code>,
otherwise <code>expr2</code>.</li>
<li><code>??=</code>: null-aware assignment. <code>v ??= expr</code>
causes <code>v</code> to be assigned <code>expr</code>
only if <code>v</code> is <code>null</code>.</li>
<li><code>x?.p</code>: null-aware access. <code>x?.p</code> evaluates to
<code>x.p</code> if <code>x</code> is not <code>null</code>,
otherwise evaluates to <code>null</code>.</li>
<li><code>x?.m()</code>: null-aware method invocation.
<code>x?.m()</code> invokes <code>m</code> only if <code>x</code> is
not <code>null</code>.</li>
</ul>
</li>
</ul>
<h3>Core library changes</h3>
<ul>
<li>
<p><code>dart:async</code></p>
<ul>
<li><code>StreamController</code> added setters for the
<code>onListen</code>, <code>onPause</code>, <code>onResume</code>
and <code>onCancel</code> callbacks.</li>
</ul>
</li>
<li>
<p><code>dart:convert</code></p>
<ul>
<li><code>LineSplitter</code> added a <code>split</code> static method
returning an <code>Iterable</code>.</li>
</ul>
</li>
<li>
<p><code>dart:core</code></p>
<ul>
<li><code>Uri</code> class now perform path normalization when a URI is
created. This
removes most <code>..</code> and <code>.</code> sequences from the URI
path. Purely relative paths
(no scheme or authority) are allowed to retain some leading
&quot;dot&quot; segments.
Also added <code>hasAbsolutePath</code>, <code>hasEmptyPath</code>, and
<code>hasScheme</code> properties.</li>
</ul>
</li>
<li>
<p><code>dart:developer</code></p>
<ul>
<li>New <code>log</code> function to transmit logging events to
Observatory.</li>
</ul>
</li>
<li>
<p><code>dart:html</code></p>
<ul>
<li><code>NodeTreeSanitizer</code> added the <code>const trusted</code>
field. It can be used instead
of defining a <code>NullTreeSanitizer</code> class when calling
<code>setInnerHtml</code> or other
methods that create DOM from text. It is also more efficient, skipping
the
creation of a <code>DocumentFragment</code>.</li>
</ul>
</li>
<li>
<p><code>dart:io</code></p>
<ul>
<li>Added two new file modes, <code>WRITE_ONLY</code> and
<code>WRITE_ONLY_APPEND</code> for opening a
file write only.
<a
href="https://github.com/dart-lang/sdk/commit/eaeecf2ed13ba6c7fbfd653c3c592974a7120960">eaeecf2</a></li>
<li>Change stdout/stderr to binary mode on Windows.
<a
href="https://github.com/dart-lang/sdk/commit/4205b2997e01f2cea8e2f44c6f46ed6259ab7277">4205b29</a></li>
</ul>
</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a
href="https://github.com/dart-lang/sdk/commit/b4fa68e03a5680483e93bd091074fbad30bf13a9"><code>b4fa68e</code></a>
Band-aid fix for issue <a
href="https://github.com/dart-lang/sdk/tree/main/pkg/issues/24191">#24191</a>.</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/00d6b50f138ad0bd2b8520f526ef5d1295ea5641"><code>00d6b50</code></a>
Add library prefixes to NO_LOCATION_SPANNABLE and MessageKind.</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/daff4e702f9658cb918a814e1cd7cf6ea7c228d1"><code>daff4e7</code></a>
[dart2js] fix inference of ??= and []??=</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/40c76bb2f845e3b4f787f2c65a46f289a4bdd5ab"><code>40c76bb</code></a>
dart2js: fail gracefully with invalid package config</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/1aecb656049ae6b976eee00f54ff7863d5d8e7b0"><code>1aecb65</code></a>
dart2js: remove trailing 0 byte when reading .packages</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/7f789484c8c51826f5cdb613ad8f19a1df7c1679"><code>7f78948</code></a>
dart2js: don't add a trailing slash when reading --packages</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/99c2010e597e15ea1a08cceac78c0984734e59f0"><code>99c2010</code></a>
Handle comparison of empty URIs (sdk/24126).</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/971f0a294e1a7b23f6b2d7cc67281cd847dfded5"><code>971f0a2</code></a>
comment docgen test</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/3e970df1fb521ccdad99bd7eb49d00292791b87f"><code>3e970df</code></a>
comment out failing docgen test</li>
<li><a
href="https://github.com/dart-lang/sdk/commit/c7e7953c24240d851f505c0a82c6e9bc705089d2"><code>c7e7953</code></a>
update dartdoc, markdown in DEPS</li>
<li>Additional commits viewable in <a
href="https://github.com/dart-lang/sdk/commits/1.12.0/pkg">compare
view</a></li>
</ul>
</details>
<br />


[![Dependabot compatibility
score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=meta&package-manager=pub&previous-version=1.11.0&new-version=1.12.0)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores)

Dependabot will resolve any conflicts with this PR as long as you don't
alter it yourself. You can also trigger a rebase manually by commenting
`@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits
that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after
your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge
and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating
it. You can achieve the same result by closing it manually
- `@dependabot show <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)


</details>

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>