Make sure Signal are disconnected when PackageModel is deleted

Contributes to CURA-8587

plugins/Marketplace/PackageList.py

@@ -55,6 +55,8 @@ class PackageList(ListModel):
     def __del__(self) -> None:
         """ When this object is deleted it will loop through all registered API requests and aborts them """
         self.cleanUpAPIRequest()
+        self.isLoadingChanged.disconnect()
+        self.hasMoreChanged.disconnect()
 
     def abortRequest(self, request_id: str) -> None:
         """Aborts a single request"""