Destroy EditorFilesystem/EditorSettings on test shutdown

[demolke]

Otherwise asan complains if a test tries to use these.

Split off from #98909

[akien-mga]

Needs a rebase to pass CI, I had made a bit of a mess on Friday evening.

[demolke]

Did the rebase - @pafuent looks like the tests introduced in #97262 are flaky on Mac, because sometimes they pass and sometimes they don't.

My change at the same commit
Passed in my project - https://github.com/demolke/godot/actions/runs/12126549905
Failed in GodotEngine - https://github.com/godotengine/godot/actions/runs/12126550499/job/33808899066

Some other recent runs that have experienced the same issue.
https://github.com/godotengine/godot/actions/runs/12107826446/job/33755156287
https://github.com/godotengine/godot/actions/runs/12095018759/job/33727746905
https://github.com/godotengine/godot/actions/runs/12094971735/job/33728735457

[pafuent]

I'll take a look at it tonight. I developed those tests on a Mac and I never saw that test being flaky. Hopefully it will be easy to reproduce it locally running it in a loop. Sorry for the inconveniences.

[pafuent]

Fixed in #99960

[Repiteo]

Thanks!