Update docker.io/library/redis Docker tag to v8

Author: renovate[bot]

paperless/docker-compose.yaml

@@ -39,7 +39,7 @@ volumes:
 
 services:
   paperless_broker:
-    image: docker.io/library/redis:7
+    image: docker.io/library/redis:8
     restart: unless-stopped
     networks:
       - paperless