Apply suggestions from code review of branch split-scan-dir-operations

Co-authored-by: Beth Probert <beth_probert@outlook.com>

tests/mock_things/mock_autofocus.py

@@ -12,6 +12,6 @@ class MockAutoFocusThing:
     # Counter for checking functions were called
     mock_call_count = {"looping_autofocus": 0}
 
-    def looping_autofocus(self, dz=2000, start="centre"):  # noqa: ARG002
+    def looping_autofocus(self, dz: int = 2000, start: str = "centre") -> None:  # noqa: ARG002
         """This function mocks autofocus with no return"""
         self.mock_call_count["looping_autofocus"] += 1

tests/mock_things/mock_background_detect.py

@@ -1,4 +1,4 @@
-"""This testing submodule contains mock autofocus things.
+"""This testing submodule contains mock background detect things.
 
 These mocks are designed to be inserted as dependencies to give specific
 functionality and returns.