Add support to Moodle 4.5 (adapt to MDL-82427)

[izendegi]

Kaixo, Iñaki

Following the tips at #49 I've tried to make the changes needed to support both Moodle 4.5 and previous versions.

It seems to work, but I haven't tested it extensively.

[iarenaza]

Kaixo Iñigo!

Lehenik eta behin, eskerrik asko petaxuagatik! Unfortunately, it doesn't seem to work with (most? all?) versions earlier to 4.5 (as seen by the CI checks failures). We need to add the "backwards compatibility" changes mentioned in #49.

Additionally, I need to expand the CI check matrix to include Moodle 4.4 and 4.5 (I didn't back in the day), and PHP 8.2 and 8.3.

I'll have a look at it as soon as I have some spare time (I expect to have some today and tomorrow), but I can't promise an ETA.

[lucaboesch]

I've added a Pull Request to re-enable functioning CI tests under #51

[KepaUrzelai]

Hello guys,

With this commit, we can now release a new version for the plugin. Only compatible with Moodle 4.2, 4.3, 4.4 and 4.5 due to PHP versions.

Thanks for working on this!