chore(deps-dev): bump coverage from 7.6.3 to 7.6.4 in /requirements (#695)

Bumps [coverage](https://github.com/nedbat/coveragepy) from 7.6.3 to 7.6.4.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@7.6.3...7.6.4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements/dev.txt

@@ -1,4 +1,4 @@
-coverage==7.6.3; python_version>="3.9"
+coverage==7.6.4; python_version>="3.9"
 coverage==7.6.1; python_version<"3.9"
 flake8==3.8.4
 pytest-cov==5.0.0