Bump tox-gh-actions from 2.3.0 to 2.4.0 in /requirements (#785)

Bumps [tox-gh-actions](https://github.com/ymyzk/tox-gh-actions) from 2.3.0 to 2.4.0.
- [Release notes](https://github.com/ymyzk/tox-gh-actions/releases)
- [Commits](ymyzk/tox-gh-actions@v2.3.0...v2.4.0)

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

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

Author: dependabot[bot]

requirements/tox.txt

@@ -1,3 +1,3 @@
 -r ./coverage.txt
 tox==3.21.1
-tox-gh-actions==2.3.0
+tox-gh-actions==2.4.0