Upgrade minimum PHP version and dependencies

[pataar]

I got a bit carried away due the fact that the new intervention/image version requires PHP 8.1.

Closes #85

This PR contains the following changes:

• Upgrade intervention/image to major version 3
• Upgrade phpunit/phpunit to major version 10
• Make properties typed
• Fix a deprecation warning when using a float value as modulo divisor
• Bump the minimum PHP version to 8.1
• Bump Github Actions to their supported versions

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This is how it went:

https://github.com/jenssegers/imagehash/assets/3403851/87ef5f46-5868-4219-9bde-a85933b892a9