chore(deps)(deps): update httpx requirement from >=0.25.0 to >=0.28.1

Updates the requirements on [httpx](https://github.com/encode/httpx) to permit the latest version.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.25.0...0.28.1)

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

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -29,7 +29,7 @@ classifiers = [
     "Typing :: Typed",
 ]
 dependencies = [
-    "httpx>=0.25.0",
+    "httpx>=0.28.1",
     "pydantic>=2.0.0",
 ]