chore: direct reference of type hint

Signed-off-by: Saquib Saifee <[email protected]>

Author: Saquib Saifee

cyclonedx/model/bom.py

@@ -665,7 +665,7 @@ def register_dependency(self, target: Dependable, depends_on: Optional[Iterable[
     def urn(self) -> str:
         return f'urn:cdx:{self.serial_number}/{self.version}'
 
-    def get_bom_link(self, bom_ref: Union[str, BomRef]) -> 'XsUri':
+    def get_bom_link(self, bom_ref: Union[str, BomRef]) -> XsUri:
         """
         Generate a BOM-Link URI.