App Passwords: Return true when rate limiting a password's last used time.

Previously we returned a `WP_Error` instance saying that the password was not found which is inaccurate.

Props dlh.
Reviewed by TimothyBlynJacobs, SergeyBiryukov.
Merges [49739] to the 5.6 branch.
Fixes #51922.

git-svn-id: https://develop.svn.wordpress.org/branches/5.6@49740 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-application-passwords.php

@@ -203,7 +203,7 @@ class WP_Application_Passwords {
 
 			// Only record activity once a day.
 			if ( $password['last_used'] + DAY_IN_SECONDS > time() ) {
-				continue;
+				return true;
 			}
 
 			$password['last_used'] = time();