Update httpx requirement from ^0.25.1 to >=0.25.1,<0.27.0

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@0.25.1...0.26.0)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:development
...

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

pyproject.toml

@@ -28,7 +28,7 @@ pytest = "^7.4.3"
 pytest-asyncio = ">=0.21.1,<0.24.0"
 pytest-cov = "^4.1.0"
 pre-commit = "^3.5.0"
-httpx = "^0.25.1"
+httpx = ">=0.25.1,<0.27.0"
 
 [build-system]
 requires = ["poetry-core>=1.0.0"]