chore(deps): update lscr.io/linuxserver/heimdall docker tag to v2021

docker-compose/heimdall/docker-compose.yaml

@@ -1,7 +1,7 @@
 ---
 services:
   heimdall:
-    image: lscr.io/linuxserver/heimdall:2.6.1
+    image: lscr.io/linuxserver/heimdall:2021.11.28
     container_name: heimdall
     environment:
       - PUID=1000