disable digest pinning for our images, since Forgejo cleans them up

Since Forgejo seems to clean up older tag versions, so older digests,
disable digest pinning for our images.
While generally resulting in undeployable config, with ansible-pull the
breakage is especially noticeable.

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

@@ -22,7 +22,7 @@
 
 services:
   keycloak:
-    image: git.hamburg.ccc.de/ccchh/oci-images/keycloak:26.4@sha256:06bfa760dfa40bd3d4305a67ce02e9dc70113151f09820a3bc6c75f5f7ece855
+    image: git.hamburg.ccc.de/ccchh/oci-images/keycloak:26.4
     pull_policy: always
     restart: unless-stopped
     command: start --optimized
@@ -58,7 +58,7 @@ services:
       POSTGRES_DB: keycloak
 
   id-invite-web:
-    image: git.hamburg.ccc.de/ccchh/id-invite/id-invite:latest@sha256:ba011f410bc1d2e112135857c236412f65b727f15197dbea1fffd955e0487a6a
+    image: git.hamburg.ccc.de/ccchh/id-invite/id-invite:latest
     command: web
     restart: unless-stopped
     networks:
@@ -84,7 +84,7 @@ services:
       - "BOTTLE_HOST=0.0.0.0"
 
   id-invite-email:
-    image: git.hamburg.ccc.de/ccchh/id-invite/id-invite:latest@sha256:ba011f410bc1d2e112135857c236412f65b727f15197dbea1fffd955e0487a6a
+    image: git.hamburg.ccc.de/ccchh/id-invite/id-invite:latest
     command: email
     restart: unless-stopped
     networks:
@@ -99,7 +99,7 @@ services:
       - "SMTP_PASSWORD={{ secret__id_no_reply_smtp }}"
 
   id-invite-keycloak:
-    image: git.hamburg.ccc.de/ccchh/id-invite/id-invite:latest@sha256:ba011f410bc1d2e112135857c236412f65b727f15197dbea1fffd955e0487a6a
+    image: git.hamburg.ccc.de/ccchh/id-invite/id-invite:latest
     command: keycloak
     restart: unless-stopped
     networks: