Fix deleteQuietly handling for symlinked directories

[Sn0wyDay]

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Summary

This PR updates FileUtils.deleteQuietly(File) so that it does not clean the target contents when the input is a symbolic link to a directory.

Previously, deleteQuietly() checked file.isDirectory() and then called cleanDirectory(file) before deleting the file. On platforms where a symbolic link to a directory is treated as a directory, this could remove the contents of the symlink target before deleting the symlink itself.

deleteDirectory() already avoids this behavior by checking !isSymlink(directory) before cleaning directory contents. This PR applies the same safety check to deleteQuietly() for consistency.

Change

Before:

if (file.isDirectory()) {
    cleanDirectory(file);
}

After:

if (file.isDirectory() && !isSymlink(file)) {
    cleanDirectory(file);
}

Tests

Added a regression test to verify that calling deleteQuietly() on a symlinked directory deletes only the symlink and preserves the target directory contents.

The following tests passed locally:

mvn -Dtest=FileUtilsCleanSymlinksTest#testDeleteQuietlyWithASymlinkDirDeletesOnlyLink test
mvn -Dtest=FileUtilsCleanSymlinksTest test

AI tooling disclosure

AI-assisted tools were used to help identify the candidate issue and draft the initial patch explanation. The final code change and test were reviewed and validated manually before submission.