fix(postgresql): change tags for some initializing tasks

When building an image, having those tasks in prepare would result in
the DB being initialized with a password, which would then be the same
on each host the image is rolled out to.

This commit prevents that from happening, the DB itself is initialized
in the deploy stage.

roles/postgresql/tasks/initialize.yml

@@ -37,15 +37,15 @@
     env:
       POSTGRES_PASSWORD: "{{ postgresql_superuser_password }}"
   register: postgresql_container
-  tags: [ 'prepare', 'prepare-postgresql' ]
+  tags: [ 'deploy', 'deploy-postgresql' ]
 
 - name: Wait for container to be initialized
   wait_for:
     path: "{{ postgresql_socket_path }}/.s.PGSQL.5432"
-  tags: [ 'prepare', 'prepare-postgresql' ]
+  tags: [ 'deploy', 'deploy-postgresql' ]
 
 - name: Stop initialized container
   community.docker.docker_container:
     name: "{{ postgresql_container_name }}"
     state: absent
-  tags: [ 'prepare', 'prepare-postgresql' ]
+  tags: [ 'deploy', 'deploy-postgresql' ]