feat: implement configurable avatar caching (#170)

- Add option to enable/disable caching
- Add configurable cache duration (default: 24 hours)
- Add cache key prefix to avoid conflicts
- Update toBase64() method to respect cache configuration
- Document cache options in config file

This fixes the issue where avatars were cached forever with no way to
configure or disable the cache, making it difficult to see setting changes.

fix/upgrading phpunit to 11 (#169)

* fix: phpunit upgrade

* Update PHPUnit tests to use attributes instead of doc-comments

- Replace @test annotations with #[Test] attributes in all test files
- Fix deprecated metadata in test methods
- Ensure compatibility with PHPUnit 11.5.3
- Prepare codebase for PHPUnit 12 compatibility

* fix: remove unused file

* fix: runner image

* fix: dropping php 8.1

* fix: platform requirements

* Update Mockery dependency to fix type declaration error

- Update mockery/mockery from ~1.3 to ^1.6.7
- Fix "Type declaration 'mixed' must be unqualified" error
- Ensure compatibility with PHPUnit 11.5.3 and PHP 8.2+

Fix `parameter.implicitlyNullable` for PHP 8.4 compatibility. (#168)

Add responsive property to help with SVG generation (#163)

* Add responsive property to help with SVG generation

* Add missing Laravel code

Merge pull request #164 from laravel-shift/l12-compatibility

Laravel 12.x Compatibility

chore

add roave/security-advisories

Update run-tests.yml

fix: dont pass null to strlen() (#134)

fix tests