When using the "Let the user choose their own password via email" method, the success message needs to be updated

[MaticSulc]

Bug report

Summary

When creating a new user and checking the "Let the user choose their own password via email" (added in #16519), the response message expects a newly generated password - resulting it being blank.

Step to reproduce

1. Create a new user and choose "Let the user choose their own password via email" as the password generation method.
2. Save and observe the response

Observed behavior

Expected behavior

The message should not contain the "The password is: ", but something along the lines of "The user will receive an e-mail to set their own password".

Environment

MODX 3.1.0-pl
PHP 8.3.8