Coding Standards: Cast gmdate( 'Z' ) to an integer before addition.

This addresses two instances of the (numeric string) `gmdate( 'Z' )` being added to an `int` value.

Affected functions:
* `upgrade_110()`
* `WP_Date_Query::validate_date_values()`

Follow-up to [942], [29925], [45424].

Props justlevine.
See #52217.

git-svn-id: https://develop.svn.wordpress.org/trunk@59465 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-admin/includes/upgrade.php

@@ -992,7 +992,7 @@ function upgrade_110() {
 
 	$time_difference = $all_options->time_difference;
 
-	$server_time    = time() + gmdate( 'Z' );
+	$server_time    = time() + (int) gmdate( 'Z' );
 	$weblogger_time = $server_time + $time_difference * HOUR_IN_SECONDS;
 	$gmt_time       = time();
 

src/wp-includes/class-wp-date-query.php

@@ -317,7 +317,7 @@ public function validate_date_values( $date_query = array() ) {
 				$_year = $date_query['year'];
 			}
 
-			$max_days_of_year = gmdate( 'z', mktime( 0, 0, 0, 12, 31, $_year ) ) + 1;
+			$max_days_of_year = (int) gmdate( 'z', mktime( 0, 0, 0, 12, 31, $_year ) ) + 1;
 		} else {
 			// Otherwise we use the max of 366 (leap-year).
 			$max_days_of_year = 366;