Re-added the imports to the conftest

These are really really needed, otherwise the tests wont run. I've added a few
more comments to further stress the importance of these.

CURA-6057

tests/conftest.py

@@ -6,10 +6,15 @@
 import unittest.mock
 import pytest
 
+# Prevents error: "PyCapsule_GetPointer called with incorrect name" with conflicting SIP configurations between Arcus and PyQt: Import Arcus and Savitar first!
+import Savitar  # Dont remove this line
+import Arcus  # No really. Don't. It needs to be there!
+from UM.Qt.QtApplication import QtApplication  # QtApplication import is required, even though it isn't used.
+# Even though your IDE says these files are not used, don't believe it. It's lying. They need to be there.
+
 from cura.CuraApplication import CuraApplication
 from cura.UI.MachineActionManager import MachineActionManager
 
-
 # Create a CuraApplication object that will be shared among all tests. It needs to be initialized.
 # Since we need to use it more that once, we create the application the first time and use its instance afterwards.
 @pytest.fixture()