Let Error API capture E_USER_DEPRECATED by default

Following introduction of DEPRECATED error type in issue #17837, it was
omitted to add E_USER_DEPRECATED to the list of error types captured by
default.

This prevented handling when error_reporting=0.

Follow-up on issue #10966, cec4549
Fixes #21795

core/error_api.php

@@ -46,7 +46,7 @@
 
 # Make sure we always capture User-defined errors regardless of ini settings
 # These can be disabled in config_inc.php, see $g_display_errors
-error_reporting( error_reporting() | E_USER_ERROR | E_USER_WARNING | E_USER_NOTICE );
+error_reporting( error_reporting() | E_USER_ERROR | E_USER_WARNING | E_USER_NOTICE | E_USER_DEPRECATED );
 
 set_error_handler( 'error_handler' );