Bump coverage from 7.6.1 to 7.6.6

Bumps [coverage](https://github.com/nedbat/coveragepy) from 7.6.1 to 7.6.6.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](https://github.com/nedbat/coveragepy/commits)

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

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

requirements-test.txt

@@ -1,3 +1,3 @@
 tox==4.23.2
-coverage==7.6.1
+coverage==7.6.6
 ruff==0.7.4