dependabot(deps-dev): update tox requirement from ~=3.7 to ~=3.25

Updates the requirements on [tox](https://github.com/tox-dev/tox) to permit the latest version.
- [Release notes](https://github.com/tox-dev/tox/releases)
- [Changelog](https://github.com/tox-dev/tox/blob/master/docs/changelog.rst)
- [Commits](tox-dev/tox@3.7.0...3.25.0)

---
updated-dependencies:
- dependency-name: tox
  dependency-type: direct:development
...

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

Author: dependabot[bot]

requirements-dev.txt

@@ -1,5 +1,5 @@
 -e .
-tox ~= 3.7
+tox ~= 3.25
 mypy
 pytest ~= 6.0
 pytest-cov