refactor(ansible): remove pgadmin database init and service tasks

Remove the Ansible tasks responsible for initializing the PgAdmin database
and starting the PgAdmin systemd service. These steps are no longer required
in the current deployment workflow.

ansible/pplg/deploy.yml

@@ -263,12 +263,6 @@
     register: pip_gunicorn
     changed_when: "'Successfully installed' in pip_gunicorn.stdout"
 
-  - name: Initialize PgAdmin database
-    ansible.builtin.command:
-      cmd: /usr/pgadmin4/venv/bin/python3 /usr/pgadmin4/web/setup.py setup-db
-      creates: "{{pgadmin_data_dir}}/pgadmin4.db"
-    become_user: "{{pgadmin_user}}"
-
   - name: Template PgAdmin local config
     ansible.builtin.template:
       src: config_local.py.j2
@@ -304,12 +298,6 @@
       mode: '0644'
     notify: restart pgadmin
 
-  - name: Enable and start PgAdmin service
-    ansible.builtin.systemd:
-      name: pgadmin
-      enabled: true
-      state: started
-      daemon_reload: true
 
   # ===========================================================================
   # OAuth2-Proxy Sidecar (Prometheus UI)