Argument #1 ($string) must be of type string, array given in trim()

Problem/Motivation

I just updated one of my Drupal 7 sites to PHP 8, and I'm now seeing this error in the logs:

TypeError: trim(): Argument #1 ($string) must be of type string, array given in trim() (line 52 of drupal/sites/all/modules/contrib/username_enumeration_prevention/username_enumeration_prevention.module).

This is coming from a bot doing a penetration test (probably) via the password reset link:
?q=user/password&name[%23post_render][]=passthru&name[%23type]=markup&name[%23markup]=echo%20XrBa7RFwh5

For now, I've wrapped the entire contents of username_enumeration_prevention_pass_validate() in a check for if (is_string($form_state['values']['name']))

I wonder, though, if the core password reset form should do better validation on values coming from the query string.