Bump httpx in the python-packages group across 1 directory

Bumps the python-packages group with 1 update in the / directory: [httpx](https://github.com/encode/httpx).


Updates `httpx` from 0.25.0 to 0.28.0
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.25.0...0.28.0)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: python-packages
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -24,7 +24,7 @@ classifiers = [
   "Programming Language :: Python :: Implementation :: CPython",
   "Programming Language :: Python :: Implementation :: PyPy",
 ]
-dependencies = ["httpx==0.25.0"]
+dependencies = ["httpx==0.28.0"]
 dynamic = ["version"]
 
 [project.optional-dependencies]