Bump coverage from 5.5 to 7.6.8

Bumps [coverage](https://github.com/nedbat/coveragepy) from 5.5 to 7.6.8.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@coverage-5.5...7.6.8)

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

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

setup.cfg

@@ -105,7 +105,7 @@ dev =
     pep8-naming         == 0.12.1  # And even your function and variable names
     mypy                ~= 1.10.0  # Do your type annotations actually work?
     pydocstyle          == 6.1.1   # Do your docstrings look like everyone else's?
-    coverage            == 5.5     # Does all your code get exercised?
+    coverage            == 7.6.8     # Does all your code get exercised?
     pytest              == 6.2.5   # Testing
     pytest-cov          == 5.0.0   # pytest + coverage = pytest-cov
     pytest-watch        == 4.2.0   # Automatic testing every time you save a file