Create catalyst-ci

[fulldecent]

This PR tries to implement a best practice documented here https://github.com/fulldecent/moodle-local_plugin_template/blob/main/.github/workflows/ci.yml

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We would like to automatically test this plug-in every month by automatically looking for the latest stable version of Moodle.

This will allow us to achieve 4.5, 5.0 and 5.1 compatibility, possibly in our sleep.

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Personally, I think the Moodle maintainer leadership is derelict in making this so difficult for our plug-in here and the millions of other plug-ins to stay up-to-date. So I think best practice today is to use a level of indirection like I am showing in this PR and I'm documenting in our best practices repo.

[mdjnelson]

Sorry, I don't see the point of this .. if you look it just tested 404 stable. I don't understand how it will automatically do it for all versions. :)

[fulldecent]

Okay, I see their documentation here:

https://github.com/catalyst/catalyst-moodle-workflows?tab=readme-ov-file#rocket-quick-start

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This CI script will test our 404 branch against 404 Moodle.

And the same CI script will test our 405 branch against 405 Moodle.

And if our develop branch has a target version of like "999" or something then it will also test that against the main version upstream.

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Using our develop version with that version "to 999" might be a good way to automatically test against new versions upstream as they are being released. And then when we release 501 or whatever then we would branch off and support that specific version.