build(deps-dev): update tox requirement from ~=4.20.0 to ~=4.21.1 in the python-packages group across 1 directory

[dependabot[bot]]

Updates the requirements on tox to permit the latest version. Updates tox to 4.21.1

Release notes

Sourced from tox's releases.

4.21.1

What's Changed

• Fix TOML configuration errors by @​gaborbernat in tox-dev/tox#3388

Full Changelog: https://github.com/tox-dev/tox/compare/4.21.0...4.21.1

Changelog

Sourced from tox's changelog.

v4.21.1 (2024-10-02)

Bugfixes - 4.21.1

- Fix error when using ``requires`` within a TOML configuration file - by :user:`gaborbernat`. (:issue:`3386`)
- Fix error when using ``deps`` within a TOML configuration file - by :user:`gaborbernat`. (:issue:`3387`)
- Multiple fixes for the TOML configuration by :user:`gaborbernat`.:

Do not fail when there is an empty command within commands.
Allow references for set_env by accepting list of dictionaries for it.
Do not try to be smart about reference unrolling, instead allow the user to control it via the extend flag,
available both for posargs and ref replacements.
The ref replacements raw key has been renamed to of. (:issue:3388)

v4.21.0 (2024-09-30)
Features - 4.21.0

• Native TOML configuration support - by :user:gaborbernat. (:issue:999)

Improved Documentation - 4.21.0

- Update Loader docs - by :user:ziima (:issue:`3352`)
v4.20.0 (2024-09-18)
Features - 4.20.0
- Separate the list dependencies functionality to a separate abstract class allowing code reuse in plugins (such as
  ``tox-uv``) - by :gaborbernat`. (:issue:`3347`)

v4.19.0 (2024-09-17)
--------------------

Features - 4.19.0


Support pypy-<major>.<minor> environment names for PyPy environments - by :user:gaborbernat. (:issue:3346)

v4.18.1 (2024-09-07)
Bugfixes - 4.18.1
- Fix and test the string spec for the ``sys.executable`` interpreter (introduced in :pull:`3325`)
  - by :user:`hroncok` (:issue:`3327`)

Improved Documentation - 4.18.1
</tr></table> 
</code></pre>
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>

<ul>
<li><a href="https://github.com/tox-dev/tox/commit/434ac18d89a843b961c8544bf74e796191c940f0"><code>434ac18</code></a> release 4.21.1</li>
<li><a href="https://github.com/tox-dev/tox/commit/34d3adc0ed537de5d4803b4e244e43eed513c839"><code>34d3adc</code></a> Fix TOML configuration errors (<a href="https://redirect.github.com/tox-dev/tox/issues/3388">#3388</a>)</li>
<li><a href="https://github.com/tox-dev/tox/commit/719b3462b58bd5c4fc12d93cb978f824bc7a610b"><code>719b346</code></a> Update installation.rst</li>
<li><a href="https://github.com/tox-dev/tox/commit/46bef9eff54c53eeced031436d2d1a068b4bfb16"><code>46bef9e</code></a> release 4.21.0</li>
<li><a href="https://github.com/tox-dev/tox/commit/cea105b7007039c830c92ae92aa5792e819ee487"><code>cea105b</code></a> True TOML config support (<a href="https://redirect.github.com/tox-dev/tox/issues/3353">#3353</a>)</li>
<li><a href="https://github.com/tox-dev/tox/commit/a04b039fe0486752ec79733b993d73ecdf282795"><code>a04b039</code></a> [pre-commit.ci] pre-commit autoupdate (<a href="https://redirect.github.com/tox-dev/tox/issues/3385">#3385</a>)</li>
<li><a href="https://github.com/tox-dev/tox/commit/f5eba31ed3aeedcb41db64fca5b624a75abff32d"><code>f5eba31</code></a> Update Loader docs (<a href="https://redirect.github.com/tox-dev/tox/issues/3352">#3352</a>)</li>
<li><a href="https://github.com/tox-dev/tox/commit/329db639b5573cf9b5990fe990a3e48789d1fc9a"><code>329db63</code></a> [pre-commit.ci] pre-commit autoupdate (<a href="https://redirect.github.com/tox-dev/tox/issues/3350">#3350</a>)</li>
<li><a href="https://github.com/tox-dev/tox/commit/f4b3bd20f268e6da78c2a89b531f364cec35b90b"><code>f4b3bd2</code></a> Bump pypa/gh-action-pypi-publish from 1.10.1 to 1.10.2 (<a href="https://redirect.github.com/tox-dev/tox/issues/3349">#3349</a>)</li>
<li>See full diff in <a href="https://github.com/tox-dev/tox/compare/4.20.0...4.21.1">compare view</a></li>
</ul>
</details>

<br />


Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.

[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)

---


Dependabot commands and options



You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@dependabot show  ignore conditions` will show all of the ignore conditions of the specified dependency
- `@dependabot ignore  major version` will close this group update PR and stop Dependabot creating any more for the specific dependency's major version (unless you unignore this specific dependency's major version or upgrade to it yourself)
- `@dependabot ignore  minor version` will close this group update PR and stop Dependabot creating any more for the specific dependency's minor version (unless you unignore this specific dependency's minor version or upgrade to it yourself)
- `@dependabot ignore ` will close this group update PR and stop Dependabot creating any more for the specific dependency (unless you unignore this specific dependency or upgrade to it yourself)
- `@dependabot unignore ` will remove all of the ignore conditions of the specified dependency
- `@dependabot unignore  ` will remove the ignore condition of the specified dependency and ignore conditions

            

[dependabot[bot]]

Superseded by #151.