Update coverage requirement from ==7.6.1 to ==7.6.4

Updates the requirements on [coverage](https://github.com/nedbat/coveragepy) to permit the latest version.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@7.6.1...7.6.4)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:development
...

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

pyproject.toml

@@ -63,7 +63,7 @@ pytest = "*"
 pytest-cov = "*"
 pytest-watch = "*"
 pytest-flake8 = "*"
-coverage = "==7.6.1"
+coverage = "==7.6.4"
 pdoc = "^15"
 more-itertools = "~=10.5.0"
 pre-commit = "==v4.0.1"