fix(crons): Add missing , in php docs (#15699)

Author: evanpurkhiser

platform-includes/crons/setup/php.mdx

@@ -96,7 +96,7 @@ $monitorConfig = new \Sentry\MonitorConfig(
     checkinMargin: 5, // Optional check-in margin in minutes
     maxRuntime: 15, // Optional max runtime in minutes
     timezone: 'Europe/Vienna', // Optional timezone
-    failureIssueThreshold: 2 //Optional failure issue threshold
+    failureIssueThreshold: 2, //Optional failure issue threshold
     recoveryThreshold: 5 // Optional recovery threshold
 );