Bump httpx[http2] from 0.25.2 to 0.26.0

Bumps [httpx[http2]](https://github.com/encode/httpx) from 0.25.2 to 0.26.0.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.25.2...0.26.0)

---
updated-dependencies:
- dependency-name: httpx[http2]
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements-dev.txt

@@ -88,7 +88,7 @@ hpack==4.0.0 ; python_full_version >= '3.6.1'
 
 httpcore==1.0.2 ; python_version >= '3.7'
 
-httpx[http2]==0.25.2 ; python_version >= '3.7'
+httpx[http2]==0.26.0 ; python_version >= '3.7'
 
 hyperframe==6.0.1 ; python_full_version >= '3.6.1'