[GHA] Configured generic reactor workflow

[alongosz]

🎫 Issue	n/a
Target	4.6+

Description:

This PR configures generic reactor workflow. The aim here is to avoid repeating GHA configuration across dozens of maintained repositories. Instead we want to have one place to rule them all.

Known issues

Not related to the idea of this workflow, but just to the linter itself:

I already see that we're going to have an issue with Symfony flavor of Yaml:

(node:1750) [TAG_RESOLVE_FAILED] YAMLWarning: Unresolved tag: !php/const at line 4, column 42:

    ibexa.core.io.flysystem.write_flags: !php/const LOCK_EX
(...)
(node:1750) [TAG_RESOLVE_FAILED] YAMLWarning: Unresolved tag: !tagged at line 20, column 39:

            $versionTargetEvaluators: !tagged ibexa.permissions.limitation_type…
                                      ^^^^^^^

!php/const, !tagged, !tagged_iterator, and more like that are valid expressions for Yaml interpreted by Symfony. I'm not sure if we can configure linter to take this into account.

Documentation:

Internal tool already internally documentent.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[alongosz]

@ibexa-yuna I've tried to add generic reactor workflow to core. It works, but the linter itself generates warnings (see the job output and PR description).

[ibexa-yuna]

@ibexa-yuna I've tried to add generic reactor workflow to core. It works, but the linter itself generates warnings (see the job output and PR description).

I think this is OKay and we just need to change the action in the reactee workflow

[alongosz]

Status: Before we merge this one, I was tasked to explore in more details what else we can add here (code style, tests). Almost all pieces are in place for that.