Refactor: Pre-process Dell catalog before parallel downloads

Moves the Dell catalog download and preparation logic from the individual driver download task to the parent function.

This prevents a race condition where multiple parallel tasks would attempt to download and extract the same catalog file simultaneously. The catalog is now prepared once before any driver downloads begin, improving efficiency and reliability.

Additionally, comments out manual garbage collection calls in the VM build UI.

FFUDevelopment/BuildFFUVM_UI.ps1

@@ -167,9 +167,9 @@ $window.Add_Closed({
             }
         }
 
-        # Garbage collection
-        [System.GC]::Collect()
-        [System.GC]::WaitForPendingFinalizers()
+        # # Garbage collection
+        # [System.GC]::Collect()
+        # [System.GC]::WaitForPendingFinalizers()
     })
 
 [void]$window.ShowDialog()