Update dependency httpx to ^0.28.0

Author: renovate[bot]

pyproject.toml

@@ -12,7 +12,7 @@ sqlalchemy = {extras = ["mypy"], version = "^2.0.39"}
 uvicorn = "^0.32.0"
 pydantic = "^2.10.6"
 psycopg2-binary = "^2.9.10"
-httpx = "^0.27.0"
+httpx = "^0.28.0"
 schedule = "^1.2.2"
 python-dateutil = "^2.9.0.post0"
 packaging = "^24.2"