fix: fastAPI user warning due to unsupported use of api_route

freqtrade/rpc/api_server/api_v1.py

@@ -77,9 +77,13 @@ router_public = APIRouter()
 router = APIRouter()
 
 
-@router_public.api_route("/ping", methods=["GET", "HEAD"], response_model=Ping, tags=["Info"])
+@router_public.get("/ping", response_model=Ping, tags=["Info"])
+@router_public.head("/ping", response_model=Ping, tags=["Info"])
 def ping():
-    """simple ping"""
+    """simple ping to check if API is responsive
+
+    Performa no internal checks, just returns poing.
+    """
     return {"status": "pong"}