build(deps): update httpx requirement from >=0.24.0 to >=0.28.1

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@0.24.0...0.28.1)

---
updated-dependencies:
- dependency-name: httpx
  dependency-version: 0.28.1
  dependency-type: direct:production
...

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

Author: dependabot[bot]

pyproject.toml

@@ -15,7 +15,7 @@ authors = [
 dependencies = [
     "fastapi>=0.104.0",
     "pydantic>=2.0.0",
-    "httpx>=0.24.0",
+    "httpx>=0.28.1",
     "websockets>=11.0",
     "python-multipart>=0.0.6",
     "uvicorn>=0.23.0",
@@ -27,18 +27,18 @@ api = [
     "fastapi>=0.104.0",
 ]
 dashboard = [
-    "httpx>=0.24.0",
+    "httpx>=0.28.1",
     "websockets>=11.0",
 ]
 sdk = [
-    "httpx>=0.24.0",
+    "httpx>=0.28.1",
 ]
 dev = [
     "pytest>=7.0.0",
     "pytest-asyncio>=0.21.0",
 ]
 all = [
-    "httpx>=0.24.0",
+    "httpx>=0.28.1",
     "websockets>=11.0",
     "pytest>=7.0.0",
     "pytest-asyncio>=0.21.0",