Update tox requirement from <3.28,>=3.20 to >=3.20,<4.1

[dependabot]

Updates the requirements on tox to permit the latest version.

Release notes

Sourced from tox's releases.

4.0.8

What's Changed

• Fix multiple substitutions on factor filtering by @​gaborbernat in tox-dev/tox#2680
• Fix requirements.txt parsing by @​gaborbernat in tox-dev/tox#2683

Full Changelog: tox-dev/tox@4.0.7...4.0.8

Changelog

Sourced from tox's changelog.

v4.0.8 (2022-12-11)

Bugfixes - 4.0.8

- Fix multiple substitution on factor filtering in ``tox.ini`` when multiple factor filters match
  - by :user:`gaborbernat`. (:issue:`2650`)
- Fix regression in ``requirements.txt`` parsing - by :user:`gaborbernat`. (:issue:`2682`)
v4.0.7 (2022-12-11)
Bugfixes - 4.0.7

• Support for --no-deps flag within the :ref:deps - by :user:gaborbernat. (:issue:2674)

v4.0.6 (2022-12-10)

Features - 4.0.6

- Fail on :ref:`pass_env`/:ref:`passenv` entries containing whitespace - by :user:`ericzolf`. (:issue:`2658`)
v4.0.5 (2022-12-09)
Bugfixes - 4.0.5

• Normalize extra names passed in (fixes extra groups not being picked up during installation) - by :user:gaborbernat. (:issue:2655)

v4.0.4 (2022-12-09)

Bugfixes - 4.0.4

- Disable logging from ``distlib.util`` and ``filelock`` as these log messages are too verbose - by :user:`gaborbernat`. (:issue:`2655`)
- Use ``!r`` and ``repr()`` to better display erroneous values in exception from ``StrConverter.to_bool()`` - by :user:`ptmcg`. (:issue:`2665`)
Improved Documentation - 4.0.4

• Document that running --showconfig or --help-ini with the -v flag will add interleaved debugging information, whereas tox v3 added extra lines at the start - by :user:jugmac00. (:issue:2622)
• Document that tox v4 errors when using -U when defining dependencies via deps - by :user:jugmac00. (:issue:2631)

v4.0.3 (2022-12-08)

... (truncated)

Commits

• 8251a7d release 4.0.8
• 3c89572 Fix requirements.txt parsing (#2683)
• 3a54b53 Fix multiple substitution on factor filtering (#2680)
• 900d90e Merge pull request #2679 from tox-dev/release-4.0.7
• 6266501 release 4.0.7
• 7c4f177 Support for --no-deps within deps (#2678)
• 36afe0c Mark keyboard interrupt flaky test
• 85b2de6 Document removal of distdir
• e23a233 Merge pull request #2675 from tox-dev/release-4.0.6
• f034ca7 release 4.0.6
• Additional commits viewable in compare view

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