Update redis Docker tag to v8

audiomuse/docker-compose.yml

@@ -1,7 +1,7 @@
 services:
   # Redis service for RQ (task queue)
   audiomuse-ai-redis:
-    image: redis:7-alpine
+    image: redis:8-alpine
     container_name: audiomuse-redis
     ports:
       - "6379:6379" # Expose Redis port to the host