phpcs: use parallel mode

[janedbal]

Ideally, available vcpus should be used...

[johnbillion]

What improvement does this give? And does GitHub Actions provide more than one core to run this in parallel during CI?

[staabm]

github actions run with 2 cores on the default instance. whether its a measurable difference need to be proved though.

[staabm]

@theofidry maybe phpcs should have some cpu core autodetection ;)

[janedbal]

What improvement does this give?

Minor CI & local speedup.

maybe phpcs should have some cpu core autodetection ;)

Yeah, ideally. Current solution is really naive.

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I dont really care about this PR much, but it feels wrong not to utilize faster solution :)

[alies-dev]

@johnbillion

What improvement does this give? And does GitHub Actions provide more than one core to run this in parallel during CI?

GH provides 2, 4, 8, 16, 64 core runners, also supports custom runners: https://docs.github.com/en/actions/using-github-hosted-runners/using-larger-runners

I see this PR very beneficial - I can remove some custom core that I wrote to utility all CPUs for different tools