Fix implicit-return in foursquare (#122843)

homeassistant/components/foursquare/__init__.py

@@ -3,6 +3,7 @@
 from http import HTTPStatus
 import logging
 
+from aiohttp import web
 import requests
 import voluptuous as vol
 
@@ -85,11 +86,11 @@ class FoursquarePushReceiver(HomeAssistantView):
     url = "/api/foursquare"
     name = "foursquare"
 
-    def __init__(self, push_secret):
+    def __init__(self, push_secret: str) -> None:
         """Initialize the OAuth callback view."""
         self.push_secret = push_secret
 
-    async def post(self, request):
+    async def post(self, request: web.Request) -> web.Response | None:
         """Accept the POST from Foursquare."""
         try:
             data = await request.json()
@@ -107,3 +108,4 @@ class FoursquarePushReceiver(HomeAssistantView):
             return self.json_message("Incorrect secret", HTTPStatus.BAD_REQUEST)
 
         request.app[KEY_HASS].bus.async_fire(EVENT_PUSH, data)
+        return None