Remove unused njsscan rules
What does this MR do?
These rules were added in !124 (merged) as a first step to migrating the rules. Since then gitlab-org/gitlab#395487 (closed) was deprioritized.
Now that work is going to recommence on gitlab-org/gitlab#395487 (closed) I'd like to clean up what I did 4 months ago since the implementation plan has changed.
This is a no-op change as these rules were never packaged or imported into semgrep.
What are the relevant issue numbers
Edited by Craig Smith