GH Actions: various updates

[jrfnl]

GH Actions: fix use of deprecated set-output

GitHub has deprecated the use of set-output (and set-state) in favour of new environment files.

This commit updates workflows to use the new methodology.

Refs:

• https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/
• https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#environment-files

GH Actions: update the xmllint-problem-matcher

The xmllint-problem-matcher action runner has released a new version which updates it to use node 16.
This gets rid of a warning which was shown in the action logs.

Note: I've suggested to the author to use long-running branches for the action runner instead, which would make this update redundant, but no telling if or when they'll respond to that, let alone if they will follow my suggestion.

Refs:

• https://github.com/korelstar/xmllint-problem-matcher/releases/tag/v1.1

🆕 GH Actions: harden the workflow against PHPCS ruleset errors

If there is a ruleset error, the cs2pr action doesn't receive an xml report and exits with a 0 error code, even though the PHPCS run failed (though not on CS errors, but on a ruleset error).

This changes the GH Actions workflow to allow for that situation and still fail the build in that case.

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👉🏻 Note: this won't get rid of all warning yet as a lot of predefined action runners also use set-output, but most of those are in the process of updating and/or have released a new version already, so the other warnings should automatically disappear over the next few weeks.

[jrfnl]

Note: PR #282 is needed to get the build to pass.

[jrfnl]

I've removed the second commit - the action runner branch has become a long-running branch, so this update is no longer needed.

[sirbrillig]

Great! Thank you!

[sirbrillig]

The PHP 7.4 static analysis failure is this, for the record:

I don't see how your changes could have caused that so I'm guessing it's just that there was an upgrade to the analyzer. If you're fine with merging, I'm fine with that.

[jrfnl]

I don't see how your changes could have caused that so I'm guessing it's just that there was an upgrade to the analyzer. If you're fine with merging, I'm fine with that.

Correct. That looks to be related to an update of PHPStan, not to this PR. If you rerun CI on 2.x, the error should also show, which would confirm that it is unrelated to this PR.

Aside from that, a fix for the PHPStan issue is ready in PR #282, so if you'd merge that first, I could rebase this PR after and you can see a clean build.

[jrfnl]

Rebased without changes to get a passing build.

[jrfnl]

FYI: Added a new second commit with some workflow hardening (and updated the PR description to match).

[sirbrillig]

👍 Thank you!