refactor(alertmanager): add state=absent support

roles/alertmanager/tasks/deploy-docker.yml

@@ -0,0 +1,21 @@
+---
+- name: Ensure container image is {{ alertmanager_state }} on host
+  community.docker.docker_image:
+    name: "{{ alertmanager_container_image_reference }}"
+    state: "{{ alertmanager_state }}"
+    source: "{{ alertmanager_container_image_source }}"
+    force_source: "{{ alertmanager_container_image_force_pull | bool }}"
+
+- name: Ensure container '{{ alertmanager_container_name }}' is {{ alertmanager_container_state }}
+  community.docker.docker_container:
+    name: "{{ alertmanager_container_name }}"
+    image: "{{ alertmanager_container_image_reference }}"
+    env: "{{ alertmanager_container_env | default(omit) }}"
+    user: "{{ alertmanager_user_info.uid | default(alertmanager_user) }}"
+    ports: "{{ alertmanager_container_ports | default(omit) }}"
+    volumes: "{{ alertmanager_container_volumes | default(omit) }}"
+    networks: "{{ alertmanager_container_networks | default(omit) }}"
+    purge_networks: "{{ alertmanager_container_purge_networks | default(omit) }}"
+    etc_hosts: "{{ alertmanager_container_etc_hosts | default(omit) }}"
+    restart_policy: "{{ alertmanager_container_restart_policy }}"
+    state: "{{ alertmanager_container_state }}"