Bump httpx from 0.27.2 to 0.28.1 (#260)

Bumps [httpx](https://github.com/encode/httpx) from 0.27.2 to 0.28.1.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.27.2...0.28.1)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.dev.txt

@@ -3,4 +3,4 @@ pylint==3.3.1
 pytest==8.3.3
 pytest-watch==4.2.0
 mypy==1.13.0
-httpx==0.27.2
+httpx==0.28.1