non-empty dctemp directory does not get deleted

[sellersj]

Describe the bug
Pretty sure that the change from moving from commons-io to pure java made it so the temp directories do not get deleted in FileUtils.delete(file)
https://github.com/jeremylong/DependencyCheck/pull/6343/files#diff-85b91249daadcc4a913e9b171dc8095e85c76e359d182046f8df56220df78278
This cause out an out disk space on my build box where I had 100-250 GB of free space. Each maven module creates about 135 MB of space.

Version of dependency-check used
The problem occurs using version 9.0.8 of the maven plugin. The issue did not exist in 9.0.7

Log file
When reporting errors, 99% of the time log file output is required. Please post the log file as a gist and provide a link in the new issue.
n/a in this case I think

To Reproduce
Steps to reproduce the behavior:

1. Run a build with the maven plugin
2. Go to the temp directory
3. See it filled with folders that start with "dctemp"

Expected behavior
That the temp files are correctly cleared out

Additional context
n/a

[sellersj]

I rolled back the change. The temp space had taken up about 160G of space.

I think that the fix would be change the delete call to something like this

Files.walk(file.toPath())
  .sorted(Comparator.reverseOrder())
  .map(Path::toFile)
  .forEach(File::delete);

[sellersj]

I tested 9.0.9-SNAPSHOT with a couple of hundred projects on a CI server and the disk usage didn't change much.

I can't tie this issue to a milestone, but that's where it was fixed.

Closing ticket.