Remove Heat environment file disabling deprecated plugins

Commit d68644386f disabled these
deprecated plugins more than three years ago.

Change-Id: I2dd2a89a7aa2c4a54882a8b0aa8d23d874c0e4cc
Closes-Bug: #1839172

ansible/roles/heat/tasks/config.yml

@@ -42,15 +42,6 @@
   notify:
     - Restart {{ item.key }} container
 
-- name: Copying over the heat-engine environment file
-  become: true
-  template:
-    src: "_deprecated.yaml"
-    dest: "{{ node_config_directory }}/{{ item }}/_deprecated.yaml"
-    mode: "0660"
-  with_items:
-    - "heat-engine"
-
 - name: Copying over heat.conf
   become: true
   vars:

ansible/roles/heat/tasks/upgrade.yml

@@ -3,5 +3,12 @@
 
 - include_tasks: bootstrap_service.yml
 
+# NOTE(priteau): Remove this task in V cycle.
+- name: Remove heat-engine environment file
+  become: true
+  file:
+    path: "{{ node_config_directory }}/heat-engine/_deprecated.yaml"
+    state: absent
+
 - name: Flush handlers
   meta: flush_handlers

ansible/roles/heat/templates/_deprecated.yaml

@@ -1,5 +0,0 @@
----
-resource_registry:
-    "OS::Heat::HARestarter":
-    "OS::Heat::SoftwareDeployments":
-    "OS::Heat::StructuredDeployments":

ansible/roles/heat/templates/heat-engine.json.j2

@@ -6,12 +6,6 @@
             "dest": "/etc/heat/heat.conf",
             "owner": "heat",
             "perm": "0600"
-        },
-        {
-            "source": "{{ container_config_directory }}/_deprecated.yaml",
-            "dest": "/etc/heat/environment.d/_deprecated.yaml",
-            "owner": "heat",
-            "perm": "0600"
         }{% if heat_policy_file is defined %},
         {
             "source": "{{ container_config_directory }}/{{ heat_policy_file }}",

releasenotes/notes/remove-heat-engine-environment-file-5f1320011b00099d.yaml

@@ -0,0 +1,7 @@
+---
+upgrade:
+  - |
+    The Heat role has stopped disabling deprecated plugins. To apply this
+    change to existing deployments, the file
+    ```/etc/kolla/heat-engine/_deprecated.yaml`` is automatically removed
+    during the upgrade.