build(deps-dev): bump httpx from 0.27.2 to 0.28.0

Bumps [httpx](https://github.com/encode/httpx) from 0.27.2 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@0.27.2...0.28.0)

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

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

Author: dependabot[bot]

requirements-dev.txt

@@ -2,7 +2,7 @@ pytest==8.3.3
 flake8==7.1.1
 pytest-cov==6.0.0
 codecov==2.1.13
-httpx==0.27.2
+httpx==0.28.0
 pylint==3.3.1
 certifi>=2023.7.22 # not directly required, pinned by Snyk to avoid a vulnerability
 requests>=2.32.0 # not directly required, pinned by Snyk to avoid a vulnerability