refactor: use fs/promises instead of rimraf package

[Phillip9587]

PR Checklist

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• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[x] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

refactor to use the rm() method instead of the rimraf package. Also moved the deleteOutDirIfEnabled() method from the WorkspaceUtils class into its own file inside the helper directory because it is the only method of the class.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information