Bump coverage from 7.6.7 to 7.6.8

Bumps [coverage](https://github.com/nedbat/coveragepy) from 7.6.7 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@7.6.7...7.6.8)

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

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -37,7 +37,7 @@ dynamic = ["version"]
 [project.optional-dependencies]
 test = [
     "codespell==2.3.0",
-    "coverage==7.6.7",
+    "coverage==7.6.8",
     "mypy==1.13.0",
     "pyserial-asyncio-fast==0.14",
     "pytest==8.3.3",

requirements_test.txt

@@ -1,5 +1,5 @@
 codespell==2.3.0
-coverage==7.6.7
+coverage==7.6.8
 mypy==1.13.0
 pre-commit==4.0.1
 pyserial-asyncio-fast==0.14