Enable testing of more than Libraries

[tatankat]

Summary of Changes

Remove Libraries subdirectory from directory configuration in phpunit config, so Component and Plugin tests are also executed.

Testing Instructions

run phpunit and see more tests being done

Actual result BEFORE applying this Pull Request

765 tests executed

Expected result AFTER applying this Pull Request

786 tests executed

Documentation Changes Required

None that I know of.

[rdeutz]

1. If you want to add more tests than you can add more testsuites.
2. Our CI fails on you change, what is not a good sign.

[tatankat]

1. If you want to add more tests than you can add more testsuites.

I do not want to add more tests. The tests are already written and part of the repository, they are just not executed.

2. Our CI fails on you change, what is not a good sign.

The CI fails on the tests that were already there. Problem is they do not fail when I run them locally. I have no idea why they fail on the CI.

[laoneo]

The problem is that in drone the tests are executed as root, so it can create the invalid folders. I made an alternative pr where I fixed the tests in #38421. Can you have a look on this pr @tatankat?

[tatankat]

@laoneo Nice, thanks for looking into it and the work done! I will close this one in favor of #38421