User creation bypasses the password errors

[torchiaf]

Setup

• Rancher version: v2.14-998c69e1d7c87d3f35fd0c5c14e01f0fbe1b7270-head
• Rancher UI: master head-90b1bc281e

Describe the bug

When creating new users, we get a webhook error if password is the same as username, but Rancher ignores the error and it creates the new user.
It' s not possible to login with the new user -> The secrets containing the user's password does not exist.

To Reproduce

• Go to Users -> Create a standard user
• Assign the same value to the username & password field.
• Click save

Expected Result

The user shouldn't be created

Screenshots

Additional context

[aalves08]

/backport v2.14.1