Merge pull request #7976 from overleaf/ho-rt-upgrade-2022

bump real time node pools to 1.21.10-gke.2000

GitOrigin-RevId: 2d5f89970de5da7037657c7f12d5a761044a0a8a

docker-compose.yml

@@ -103,7 +103,7 @@ services:
 
     mongo:
         restart: always
-        image: mongo:4.2
+        image: mongo:4.0
         container_name: mongo
         expose:
             - 27017