Return empty string instead of asterisk when class line cannot be determined

Changed get_class_line() to return "" instead of "*" when inspect.getsourcelines() fails, making it consistent with the pytest implementation and leaving the field blank when the line number cannot be determined.

Co-authored-by: eleanorjboyd <[email protected]>

Author: Copilot

python_files/unittestadapter/pvsc_utils.py

@@ -109,7 +109,7 @@ def get_class_line(test_case: unittest.TestCase) -> str:
         _sourcelines, lineno = inspect.getsourcelines(test_class)
         return str(lineno)
     except Exception:
-        return "*"
+        return ""
 
 
 def get_source_line(obj) -> str: