chore: update requirements.txt with pinned minimum versions

requirements.txt

@@ -1,11 +1,8 @@
-# Runtime
-fastapi>=0.115.0
-uvicorn[standard]>=0.30.0
-fastmcp>=2.0.0
+fastapi>=0.115
+uvicorn[standard]>=0.23
+pydantic>=2.6
+requests>=2.31
+pytest>=8.4
 mcp>=1.0.0
-pydantic>=2.8.0
-jinja2>=3.1.0
-python-dotenv>=1.0.1
-
-# Testing
-pytest>=8.0.0
+starlette>=0.49.1
+sse-starlette>=3.4.4