MNT: (deps): Bump coverage from 6.4.4 to 7.6.1 in /ci

Bumps [coverage](https://github.com/nedbat/coveragepy) from 6.4.4 to 7.6.1.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@6.4.4...7.6.1)

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

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

ci/test_requirements.txt

@@ -1,4 +1,4 @@
 pytest==7.1.3
 netCDF4==1.6.1
-coverage==6.4.4
+coverage==7.6.1
 vcrpy==4.2.1