Make maubot automatically create its own user.

roles/custom/matrix-bot-maubot/defaults/main.yml

@@ -5,6 +5,11 @@
 
 matrix_bot_maubot_enabled: true
 
+matrix_bot_maubot_login: bot.maubot
+# This is just initial password and it will not manage subsequent password changes.
+# Use a tool like synapse-admin if you need to change it.
+matrix_bot_maubot_initial_password: "{{ lookup('password', '/dev/null', length=64 }}"
+
 matrix_bot_maubot_scheme: https
 matrix_bot_maubot_hostname: ''
 matrix_bot_maubot_path_prefix: /_matrix/maubot