Laravel 12 compatibility

[coxlr]

Update dependencies and GitHub action to be compatible with Laravel 12.x.
Drop support for old Laravel versions
Add new GitHub action to auto update change log on release
Add new GitHub action to auto merge dependabot merge requests

[what-the-diff]

PR Summary

• Automated merging of regular updates: Establishes an automated process which combines changes from Dependabot PRs based on version updates. The file .github/workflows/dependabot-auto-merge.yml has been created for this purpose.
• Given more power to fixer workflow: The PHP CS Fixer workflow can now write to the contents, which improves its ability to make changes automatically. The update took place in the .github/workflows/php-cs-fixer.yml file.
• Removal of excess workflow: The older .github/workflows/psalm.yml workflow has been taken out, suggesting less reliance on the Psalm tool.
• Better software compatibility for testing: The script that runs tests is now tuned for the latest PHP and Laravel versions. Obsolete versions have been excluded, leading to more efficient testing processes.
• Automated changelog updates: The introduction of the .github/workflows/update-changelog.yml file means that the changelog will be automatically updated upon release.
• Fixed Packagist Badge in README: This correction makes the Packagist badge portray accurate information in the README.md file.
• Adjusted PHP requirements: The PHP requirement is now updated to ^8.2 which represents an increase in minimum required version in the composer.json file for the project.
• Updated testing requirements: The version constraints for testbench and PHPUnit have been updated in the composer.json file, which improves the compatibility of our tests with new versions.
• Removal of redundant Psalm references in composer: Psalm script reference is no longer necessary and has been removed from composer.json.
• Modernized PHPUnit configuration: The updates made to phpunit.xml.dist make it compatible with the newer versions of PHPUnit.
• Removal of unnecessary Psalm configuration file: The psalm.xml.dist file, related to the Psalm tool, has been removed given its redundancy.