Delete edxapp_migrate.yml

I'm not sure where we use this and I was unable to find any references to it anywhere.

playbooks/edx-east/edxapp_migrate.yml

-- name: Run edxapp migrations
-  hosts: all
-  become: False
-  gather_facts: False
-  vars:
-    db_dry_run: "--list"
-  roles:
-    - edxapp
-  tasks:
-    - name: migrate lms
-      shell: "python manage.py lms migrate --database {{ item }} --noinput {{ db_dry_run }} --settings=aws"
-      args:
-        chdir: "{{ edxapp_code_dir }}"
-      environment:
-        DB_MIGRATION_USER: "{{ COMMON_MYSQL_MIGRATE_USER }}"
-        DB_MIGRATION_PASS: "{{ COMMON_MYSQL_MIGRATE_PASS }}"
-      # Migrate any database in the config, but not the read_replica
-      when: item != 'read_replica'
-      with_items:
-        - "{{ lms_auth_config.DATABASES.keys() }}"
-      tags:
-        - always
-    - name: migrate cms
-      shell: "python manage.py cms migrate --database {{ item }} --noinput {{ db_dry_run }} --settings=aws"
-      args:
-        chdir: "{{ edxapp_code_dir }}"
-      environment:
-        DB_MIGRATION_USER: "{{ COMMON_MYSQL_MIGRATE_USER }}"
-        DB_MIGRATION_PASS: "{{ COMMON_MYSQL_MIGRATE_PASS }}"
-      # Migrate any database in the config, but not the read_replica
-      when: item != 'read_replica'
-      with_items:
-        - "{{ cms_auth_config.DATABASES.keys() }}"
-      tags:
-        - always