chore(deps): update dependency tox to v4.50.3 (#976)

This PR contains the following updates:

| Package | Change |
[Age](https://docs.renovatebot.com/merge-confidence/) |
[Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [tox](https://redirect.github.com/tox-dev/tox)
([changelog](https://tox.wiki/en/latest/changelog.html)) | `==4.50.2` →
`==4.50.3` |
![age](https://developer.mend.io/api/mc/badges/age/pypi/tox/4.50.3?slim=true)
|
![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/tox/4.50.2/4.50.3?slim=true)
|

---

### Release Notes

<details>
<summary>tox-dev/tox (tox)</summary>

###
[`v4.50.3`](https://redirect.github.com/tox-dev/tox/releases/tag/4.50.3)

[Compare
Source](https://redirect.github.com/tox-dev/tox/compare/4.50.2...4.50.3)

<!-- Release notes generated using configuration in .github/release.yaml
at 4.50.3 -->

#### What's Changed

- 🐛 fix(pkg): distinguish free-threaded Python in wheel build env by
[@&#8203;gaborbernat](https://redirect.github.com/gaborbernat) in
[#&#8203;3891](https://redirect.github.com/tox-dev/tox/pull/3891)

**Full Changelog**:
<tox-dev/tox@4.50.2...4.50.3>

</details>

---

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requirements-dev.txt

@@ -1,7 +1,7 @@
 -r requirements.txt
 -r requirements-test.txt
-tox==4.50.2 ; python_version >= "3.10"
-tox==4.50.2 ; python_version < "3.10"
+tox==4.50.3 ; python_version >= "3.10"
+tox==4.50.3 ; python_version < "3.10"
 wheel==0.46.3
 Sphinx==9.0.4 ; python_version >= "3.11"
 Sphinx==7.4.7 ; python_version < "3.11"