Accept null and 0 for microseconds argument in stream_select()

PHP 8.0 did not accept null for the usec argument, PHP 8.1 only
accepts null. This means you can't easily write code compatible
with both without triggering at least a deprecation warning.
Drop the deprecation warning for now.

Closes GH-7617.

Author: zobo

ext/standard/streamsfuncs.c

@@ -790,9 +790,7 @@ PHP_FUNCTION(stream_select)
 	PHP_SAFE_MAX_FD(max_fd, max_set_count);
 
 	if (secnull && !usecnull) {
-		if (usec == 0) {
-			php_error_docref(NULL, E_DEPRECATED, "Argument #5 ($microseconds) should be null instead of 0 when argument #4 ($seconds) is null");
-		} else {
+		if (usec != 0) {
 			zend_argument_value_error(5, "must be null when argument #4 ($seconds) is null");
 			RETURN_THROWS();
 		}

ext/standard/tests/streams/stream_select_null_usec.phpt

@@ -27,7 +27,6 @@ array(1) {
   resource(%d) of type (stream)
 }
 
-8192 stream_select(): Argument #5 ($microseconds) should be null instead of 0 when argument #4 ($seconds) is null
 
 Fatal error: Uncaught ValueError: stream_select(): Argument #5 ($microseconds) must be null when argument #4 ($seconds) is null in %s
 Stack trace: