fix: upgrade actions for Node.js 24 support (#57)

* fix: upgrade all GitHub Actions to latest versions for Node.js 24 support
* fix: Pin actions/upload-pages-artifact to v5.0.0
   actions/upload-pages-artifact#142

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Co-authored-by: MiniMax <[email protected]>

Merge pull request #56 from sphinx-notes/incrbuild

Incrbuild attempt 2

ci: Use image ubuntu-latest

Increase traceback length

Bump default python version from 3.10 -> 3.12

As 3.10 is not longer actively supported.
See also https://endoflife.date/python

Use original actions/upload-pages-artifact (#38)

Since actions/upload-pages-artifact#94 is
merged.

docs: Set trigger branch

docs: Move beta warning ahead

docs: Use domain sphinx.silverrainz.me

Correct dir name