Cache node_modules between jobs and DRY up semgrep jobs ever so slightly
ci: Cache node_modules between jobs
ci: DRY up semgrep jobs
This may seem a bit unnecessary, but in future we may want to:
- Install some packages on the semgrep image (e.g., jq)
- Pin & update the semgrep image version
Having this extracted to a single place makes this things a bit easier.
Edited by Mark Florian