Problem:
If you have this repo forked, the workflow for Coverity Scan creates a lot of
spammy emails about that workflow failing.
Solution:
Check for the presence of `COVERITY_SCAN_TOKEN` and `COVERITY_SCAN_EMAIL` at the
very start of `.github/workflows/coverity.yml`, skip the rest of the workflow if
they are absent. Unfortunately, Github Actions don't offer a straightforward way
of doing that, so using [this workaround](https://github.com/orgs/community/discussions/25280)).