Ensure this package is compatible with PHP 8.5.

Acceptance Criteria

• composer.json version constraint updated to include PHP 8.5 (e.g. ^8.2|^8.5 or >=8.2)
• CI matrix includes a PHP 8.5 job and all tests pass with zero failures on PHP 8.5
• Any PHP 8.5 deprecation warnings or compatibility issues in package source are resolved
• README version support table updated to include PHP 8.5
• composer update completes without conflicts under PHP 8.5

WSJF

Acceptance Criteria

• laravel-sign-in-with-apple installs and runs without errors on PHP 8.5
• All existing tests pass on PHP 8.5 in CI
• composer.json requires constraint is updated to include PHP 8.5
• No deprecated PHP 8.5 features are used in the codebase