build(deps): bump coverage from 7.5.3 to 7.5.4 in /requirements (#271)

Bumps [coverage](https://github.com/nedbat/coveragepy) from 7.5.3 to 7.5.4.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@7.5.3...7.5.4)

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

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

requirements/_tests.txt

@@ -1,5 +1,5 @@
 coverage ==7.2.7; python_version < '3.8'
-coverage ==7.5.3; python_version >= '3.8'
+coverage ==7.5.4; python_version >= '3.8'
 pytest ==7.4.3; python_version < '3.8'
 pytest ==8.2.2; python_version >= '3.8'
 pytest-cov ==5.0.0