Bump httpx[http2] from 0.27.2 to 0.28.0 in /src (#45)

Bumps [httpx[http2]](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[http2]
  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>

src/requirements.txt

@@ -18,7 +18,7 @@ hpack==4.0.0
     # via h2
 httpcore==1.0.7
     # via httpx
-httpx[http2]==0.27.2
+httpx[http2]==0.28.0
     # via -r requirements.in
 hyperframe==6.0.1
     # via h2
@@ -31,6 +31,4 @@ ruamel-yaml==0.18.6
 ruamel-yaml-clib==0.2.12
     # via ruamel-yaml
 sniffio==1.3.1
-    # via
-    #   anyio
-    #   httpx
+    # via anyio