fix: increase minimum versions for starlette and uvicorn

Increase minimum versions for starlette and uvicorn to avoid
compatibility issues with lowest-direct dependency resolution.

The previous minimum versions (starlette>=0.27, uvicorn>=0.31.1)
allowed uvicorn 0.32.x which has a bug where uvicorn.loops.auto
module is missing the auto_loop_setup attribute, causing test
failures on Ubuntu runners.

Updated to:
- starlette>=0.40.0 (from 0.27)
- uvicorn>=0.33.0 (from 0.31.1)

This ensures lowest-direct resolution picks versions that are
compatible with the current codebase.

Github-Issue: #1325

Author: felixweinberger

pyproject.toml

@@ -26,11 +26,11 @@ dependencies = [
     "httpx>=0.27.1",
     "httpx-sse>=0.4",
     "pydantic>=2.11.0,<3.0.0",
-    "starlette>=0.27",
+    "starlette>=0.40.0",
     "python-multipart>=0.0.9",
     "sse-starlette>=1.6.1",
     "pydantic-settings>=2.5.2",
-    "uvicorn>=0.31.1; sys_platform != 'emscripten'",
+    "uvicorn>=0.33.0; sys_platform != 'emscripten'",
     "jsonschema>=4.20.0",
     "pywin32>=310; sys_platform == 'win32'",
 ]