Bump tox from 4.28.1 to 4.28.3 (#2764)

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

@@ -9,6 +9,6 @@ pre-commit==4.2.0
 pygithub==2.6.1
 requests==2.32.4
 ruff==0.12.4
-tox==4.28.1
+tox==4.28.3
 urllib3>=2.2.2 # not directly required, pinned by Snyk to avoid a vulnerability
 zipp>=3.19.1 # not directly required, pinned by Snyk to avoid a vulnerability