Add support for Composer version 2

[Ayesh]

Hi Cameron,
Composer 2 is about to be released, and it has composer-plugin-api version 2. This PR updates the version constraint in composer.json to ^1 || ^2 so we can support both composer versions.

See What's new in Composer 2 and UPGRADE-2.0 for more changes in API. Empty methods \cweagans\Composer\Plugin\Patches::deactivate() and \cweagans\Composer\Plugin\Patches::uninstall are added to make it compatible both versions.

I will make a PR to the cweagans/composer-configurable-plugin to update its composer/composer version constraint because this package depends on it.

Related: composer/composer#8726

Thank you 🙏.

[cweagans]

Thanks for this! I'm going to hold off on merging this for the time being, since the plugin won't actually work in Composer 2 with this PR. If you don't mind, I'll build off of this once I have some time and then get it merged in!

[Ayesh]

Thanks @cweagans for your time. May I ask what is broken with Composer 2? It took me some fiddling, but I could get the plugin to work with composer 2.

I didn't make extensive tests with exclusion patterns and separate patch files, but my package was indeed patched when downloaded.

Because this plugin depends on another library that brings the configuration trait, I had to add these two got repos as path repos in the test project composer.json, so they are loaded from my forks instead of the upstream.

If there's anything I can help, I'd be eager to work on them. But of course please take time. Thank you.

[CDRO]

This plugin is such a corner stone in most of our projects, that I'd be glad to sponsor some development time if it allows you to release a version that is compatible with composer v2

[cweagans]

@CDRO there is already a release. 1.7.0

[CDRO]

Ah yes, thanks for pointing that out, sometimes I should wait for the second coffee to kick in before asking a question :-)