Bump tox from 4.28.4 to 4.29.0 (#4)

Bumps [tox](https://github.com/tox-dev/tox) from 4.28.4 to 4.29.0.
- [Release notes](https://github.com/tox-dev/tox/releases)
- [Changelog](https://github.com/tox-dev/tox/blob/main/docs/changelog.rst)
- [Commits](tox-dev/tox@4.28.4...4.29.0)

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

Author: dependabot[bot]

requirements.dev.txt

@@ -1,2 +1,2 @@
 # Docs are always built on a specific Python version; see RTD and tox config files.
-tox == 4.28.4
+tox == 4.29.0