refactor: retire EDXAPP_EXTRA_REQUIREMENTS

Implements:
- edx/edx-arch-experiments#1000

Author: robrap

playbooks/roles/edxapp/defaults/main.yml

@@ -522,10 +522,8 @@ EDXAPP_UPDATE_STATIC_FILES_KEY: false
 
 EDXAPP_INSTALL_PRIVATE_REQUIREMENTS: false
 
-# Do NOT use EDXAPP_EXTRA_REQUIREMENTS.
-# This setting has been deprecated. Use EDXAPP_PRIVATE_REQUIREMENTS instead.
-# See argocd/applications/edxapp-lms/docs/decisions/0001-consolidate-edxapp-private-requirements.rst
-EDXAPP_EXTRA_REQUIREMENTS: []
+# EDXAPP_EXTRA_REQUIREMENTS has been deprecated and removed. All dependencies
+# have been moved to EDXAPP_PRIVATE_REQUIREMENTS.
 
 # These defaults for EDXAPP_PRIVATE_REQUIREMENTS are used for Edge and
 # sandboxes in EC2. Post containerization, there will be a single

playbooks/roles/edxapp/tasks/deploy.yml

@@ -166,7 +166,7 @@
   tags:
     - install
     - install:app-requirements
-  
+
 - name: Install local edxapp requirements
   command: "{{ edxapp_venv_dir }}/bin/pip install -e {{ edxapp_code_dir }}/."
   become_user: "{{ edxapp_user }}"
@@ -197,24 +197,6 @@
     - install
     - install:app-requirements
 
-# Install any custom extra requirements if defined in EDXAPP_EXTRA_REQUIREMENTS.
-- name: install python extra requirements
-  pip:
-    name: "{{ item.name }}"
-    version: "{{ item.version|default(omit) }}"
-    extra_args: "--exists-action w {{ item.extra_args|default('') }}"
-    virtualenv: "{{ edxapp_venv_dir }}"
-    state: present
-  with_items: "{{ EDXAPP_EXTRA_REQUIREMENTS }}"
-  become_user: "{{ edxapp_user }}"
-  register: edxapp_install_extra_python_reqs
-  until: edxapp_install_extra_python_reqs is succeeded
-  retries: 5
-  delay: 15
-  tags:
-    - install
-    - install:app-requirements
-
 - name: "Install Datadog APM requirements"
   when: EDXAPP_DATADOG_ENABLE
   pip: