Unit test fixes

[timhunt]

When I upgarded our to CodeRunner 5.1.1 running on PHP 8.0 we got some issues with the unit tests:

1. There was an error because of an (unecessary) use statement above the namespace statement in one file.
2. Someone, or Jobe standbox thinks that PHP is not an aviable language (even though Jobe is implemented in PHP!) So I added a check for the language being available to those unit tests.
3. And I updated the github action config to: a) Test with PHP8 as well as other versions. b) Run the tests with Moodle 4.1 and master, as well as 4.0. I can see you have been working on fixing some of the fails on the devel branch, so I did not do more.

Let me know if you would like me to change any of this.

[timhunt]

Hi @trampgeek, did you see this?

[trampgeek]

Hi Tim, sorry, yes I did see this. I had done a lot of code-polishing on the tests in my development branch so to avoid a merge conflict down the line I just manually merged your changes into development. But I'll merge your pull request into master now anyway and can resolve the conflicts when I merge development back into master later on.

I have two interns working on coderunner over the break. Lots of fun action. But we can't reproduce or explain the 'missing PHP error' you got. Unless someone deliberately removed that functionality by deleting the file php_task.php from /application/libraries but that seems highly unlikely.

Thanks for the pull request and apologies for not acknowledging earlier.

[timhunt]

No worries. Thanks for merging it.