Bump httpx from 0.27.2 to 0.28.1

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:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements.txt

@@ -14,7 +14,7 @@ distro==1.9.0
 frozenlist==1.5.0
 h11==0.14.0
 httpcore==1.0.7
-httpx==0.27.2
+httpx==0.28.1
 httpx-sse==0.4.0
 idna==3.10
 jiter==0.8.2