Speed up tests (#14421)

Don't re-load os yaml every time

LibreNMS/Poller.php

@@ -83,7 +83,7 @@ class Poller
         $polled = 0;
         $this->printHeader();
 
-        if (Debug::isEnabled()) {
+        if (Debug::isEnabled() && ! defined('PHPUNIT_RUNNING')) {
             \LibreNMS\Util\OS::updateCache(true); // Force update of OS Cache
         }
 

phpunit.xml

@@ -40,5 +40,6 @@
     <server name="QUEUE_CONNECTION" value="sync"/>
     <server name="SESSION_DRIVER" value="array"/>
     <server name="DB_CONNECTION" value="testing"/>
+    <const name="PHPUNIT_RUNNING" value="true"/>
   </php>
 </phpunit>