Use Maven#removeTestCompileSourceRoot instead of Iterator#remove

[laeubi]

FYI @hd42 @akurtakov

Fixes warnings:

[WARNING] Direct modification of testCompileSourceRoots through iterator.remove() is deprecated
 and will not work in Maven 4.0.0. Please use the add/remove methods instead.
 If you're using a plugin that causes this warning, please upgrade to the latest version and report an issue if the 
warning persists. To disable these warnings, set -Dmaven.project.sourceRoots.warningsDisabled=true
on the command line, in the .mvn/maven.config file, or in project POM properties.

[laeubi]

This will require Maven 3.9.11, so I'd like to delay it until after the Tycho 5.0.0 release.

[github-actions]

Test Results

1 008 files  ±0  1 008 suites  ±0   4h 54m 18s ⏱️ - 39m 4s
1 293 tests ±0  1 272 ✅ ±0  20 💤 ±0  1 ❌ ±0 
3 879 runs  ±0  3 814 ✅ ±0  64 💤 ±0  1 ❌ ±0 

For more details on these failures, see this check.

Results for commit 2485564. ± Comparison against base commit db7744f.

♻️ This comment has been updated with latest results.

[sratz]

I think we must first copy the list, the implicit iterator of the for-each loop does not play well together with calling remove() on the same list instance.

-for (String testCompileRoot : project.getTestCompileSourceRoots()) {
+for (String testCompileRoot : new ArrayList<>(project.getTestCompileSourceRoots())) {

[laeubi]

@sratz while this is true in general and I had the same feeling before when adapting the code, we immediately return when finding a match here so it is okay in this case.