Action matrix - php version

[tomasnorre]

I would suggest extending the action matrix to include all supported PHP versions (#35).

I would suggest to run composer install with --prefer-lowest and without to have both lowest and highest possible dependencies tested.

[webignition]

Supported PHP versions are now 8.3 and 8.4 as of version 1.1.

@tomasnorre I'd appreciate you creating a PR to update the relevant build matrices to handle running composer with and without --prefer-lowest as I'm not certain of the best way to handle this.

[tomasnorre]

You can assign me, then I'll not forget.