feat: consolidate non deprecated 8.9 image

Author: monavari-lebrecht

fiori-app/webapp/config/8.9/docker-compose.yml

@@ -97,7 +97,7 @@ services:
 
   camunda:
     container_name: camunda
-    image: camunda/camunda:SNAPSHOT
+    image: camunda/camunda:8.9
     environment:
       - DATABASE=elasticsearch 
       - 'JAVA_TOOL_OPTIONS=-Xms512m -Xmx1g'