Addressing SonarQube issue

Author: adrianoaru-nhs

pages/datasets/investigation_dataset_page.py

@@ -576,7 +576,7 @@ def get_dataset_section(self, dataset_section_name: str) -> Locator | None:
         return section_found
 
     def is_dataset_section_on_page(
-        self, dataset_section: Union[str, List[str]], should_be_present: bool = True
+        self, dataset_section: str | List[str], should_be_present: bool = True
     ) -> None:
         """
         Asserts whether the specified dataset section(s) are present or not on the page.