build(deps): bump coverage from 7.2.7 to 7.3.1

Bumps [coverage](https://github.com/nedbat/coveragepy) from 7.2.7 to 7.3.1.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@7.2.7...7.3.1)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements/test.txt

@@ -4,4 +4,4 @@
 -r pinned.txt
 
 # coverage measurement
-coverage==7.2.7
+coverage==7.3.1