use full image source and set version for all Chaosknoten compose images

Use a full image source and set and explicit version for all images in
Chaosknoten (docker-)compose files.
With Renovate now set up, it is feasible to explicitly set versions.

resources/chaosknoten/tickets/docker_compose/compose.yaml.j2

@@ -11,9 +11,9 @@ services:
     networks:
       backend:
     restart: unless-stopped
-  
+
   redis:
-    image: docker.io/library/redis:7
+    image: docker.io/library/redis:7.4.6
     ports:
       - "6379:6379"
     volumes: