Fix docker CI. (#1494)

Backport of ansible-collections/community.docker#50 to stable-1.

tests/integration/targets/docker_stack_task_info/tasks/test_stack_task_info.yml

@@ -74,7 +74,7 @@
       that:
         - 'output.results | type_debug == "list"'
         - 'output.results[0].DesiredState == "Running"'
-        - 'output.results[0].Image == docker_test_image_busybox ~ ":latest"'
+        - 'output.results[0].Image == docker_test_image_busybox'
         - 'output.results[0].Name == "test_stack_busybox.1"'
 
   always:

tests/integration/targets/docker_stack_task_info/templates/stack_compose_base.yml

@@ -1,5 +1,5 @@
 version: '3'
 services:
     busybox:
-        image: "{{ docker_test_image_busybox }}:latest"
+        image: "{{ docker_test_image_busybox }}"
         command: sleep 3600

tests/integration/targets/docker_stack_task_info/vars/main.yml

@@ -2,7 +2,7 @@ stack_compose_base:
     version: '3'
     services:
         busybox:
-            image: "{{ docker_test_image_busybox }}:latest"
+            image: "{{ docker_test_image_busybox }}"
             command: sleep 3600
 
 stack_compose_overrides: