sanitize_title_with_dashes fatal error when query var value is an array in php 8

[mouhdev]

Using latest WordPress development version 6.3-alpha-55505-src, when submitting a form with field values that are array, and the array key is one of WordPress query vars, that causing sanitize error for 'post_name' parameter in get_posts function.

Example to replicate:

• make sure to register custom post type E.g custom_post_type.
• submit the following form on your test WordPress website.

  <form method="post" action="">
  <input type="text" name="custom_post_type['post_title']" value="This is a test post">
  <input type="submit" value="Send">
  </form>