Switch to cweagans/composer-patches

[herndlm]

Alternative to #2304

upsides:

• supports PHP 5.3+ in v1 which receives still bug and security fixes

downsides:

• v2 (going to be released soon) will need PHP 8+
• does not support version-conditional patches, e.g. the paratest patch for PHP 7.2 will always fail and be skipped

docs are at https://github.com/cweagans/composer-patches/blob/1.x/README.md

[herndlm]

I still don't like the patch failures because of non-matching PHP version, but apart from that it is as good as it gets I suppose.

[ondrejmirtes]

If there's something in patches that isn't supported (like @version ^4.0?), please remove those lines.

[phpstan-bot]

This pull request has been marked as ready for review.

[herndlm]

done, just to make sure that I communicate this properly. Because of the missing PHP version info support in patches, it results in the following with every composer install (except on PHP 7.2 of course :)):

Gathering patches for dependencies. This might take a minute.
  - Installing brianium/paratest (v6.6.2): Extracting archive
  - Applying patches for brianium/paratest
    patches/paratest.patch (0)
   Could not apply patch! Skipping. The error was: Cannot apply patch patches/paratest.patch

apart from that all seems to be fine though.

[ondrejmirtes]

Thank you!