Bump types-python-dateutil from 2.9.0.20240316 to 2.9.0.20240821 (#50)

Bumps [types-python-dateutil](https://github.com/python/typeshed) from
2.9.0.20240316 to 2.9.0.20240821.
<details>
<summary>Commits</summary>
<ul>
<li>See full diff in <a
href="https://github.com/python/typeshed/commits">compare view</a></li>
</ul>
</details>
<br />

[![Dependabot compatibility
score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=types-python-dateutil&package-manager=pip&previous-version=2.9.0.20240316&new-version=2.9.0.20240821)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores)

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)

---

<details>
<summary>Dependabot commands and options</summary>
<br />

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 <dependency name> ignore conditions` will show all
of the ignore conditions of the specified dependency
- `@dependabot ignore this major version` will close this PR and stop
Dependabot creating any more for this major version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop
Dependabot creating any more for this minor version (unless you reopen
the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop
Dependabot creating any more for this dependency (unless you reopen the
PR or upgrade to it yourself)

</details>

Author: Marenz

pyproject.toml

@@ -74,7 +74,7 @@ dev-mypy = [
   "mypy == 1.11.2",
   "grpc-stubs == 1.53.0.5",               # This dependency introduces breaking changes in patch releases
   "types-Markdown == 3.7.0.20240822",
-  "types-python-dateutil==2.9.0.20240316",
+  "types-python-dateutil==2.9.0.20240821",
   # For checking the noxfile, docs/ script, and tests
   "frequenz-dispatch[dev-mkdocs,dev-noxfile,dev-pytest]",
 ]