Bump httpx from 0.27.0 to 0.28.1 (#19)

Bumps [httpx](https://github.com/encode/httpx) from 0.27.0 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@0.27.0...0.28.1)

---
updated-dependencies:
- dependency-name: httpx
  dependency-version: 0.28.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: deeptha-srirangam <146122587+deeptha-srirangam@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -8,5 +8,5 @@ Requests==2.32.5
 types-requests==2.32.4.20250611
 uvicorn==0.35.0
 pytest==8.4.1
+httpx==0.28.1
 pytest-cov==7.0.0
-httpx==0.27.0