build(deps-dev): bump diff-cover from 8.0.3 to 9.0.0 (#17876)

Bumps [diff-cover](https://github.com/Bachmann1234/diff-cover) from 8.0.3 to 9.0.0.
- [Release notes](https://github.com/Bachmann1234/diff-cover/releases)
- [Changelog](https://github.com/Bachmann1234/diff_cover/blob/main/CHANGELOG)
- [Commits](Bachmann1234/diff_cover@v8.0.3...v9.0.0)

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

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

setup.py

@@ -45,7 +45,7 @@
 dev_dependencies = [
     "build==1.2.1",
     "coverage==7.4.3",
-    "diff-cover==8.0.3",
+    "diff-cover==9.0.0",
     "pre-commit==3.5.0; python_version < '3.9'",
     "pre-commit==3.6.2; python_version >= '3.9'",
     "py3createtorrent==1.2.0",