Cleanup source_type type hints in device tracker components (#126592)

tests/components/device_tracker/common.py

@@ -69,7 +69,7 @@ class MockScannerEntity(ScannerEntity):
         self._mac_address = "ad:de:ef:be:ed:fe"
 
     @property
-    def source_type(self):
+    def source_type(self) -> SourceType:
         """Return the source type, eg gps or router, of the device."""
         return SourceType.ROUTER
 

tests/components/device_tracker/test_config_entry.py

@@ -162,7 +162,7 @@ class MockTrackerEntity(TrackerEntity):
         return self._battery_level
 
     @property
-    def source_type(self) -> SourceType | str:
+    def source_type(self) -> SourceType:
         """Return the source type, eg gps or router, of the device."""
         return SourceType.GPS
 
@@ -249,7 +249,7 @@ class MockScannerEntity(ScannerEntity):
         return False
 
     @property
-    def source_type(self) -> SourceType | str:
+    def source_type(self) -> SourceType:
         """Return the source type, eg gps or router, of the device."""
         return SourceType.ROUTER