ukify: include the invalid value in boolean errors

The invalid-boolean error contains a literal f-string prefix and
placeholder, hiding the value that failed to parse. Format the message
to include the rejected value.

(cherry picked from commit aeef38045e74dc585088a64c601166f989705d75)

src/ukify/ukify.py

@@ -1935,7 +1935,7 @@ class ConfigItem:
             return True
         if s_l in {'0', 'false', 'no', 'n', 'f', 'off'}:
             return False
-        raise ValueError('f"Invalid boolean literal: {s!r}')
+        raise ValueError(f'Invalid boolean literal: {s!r}')
 
     # arguments for argparse.ArgumentParser.add_argument()
     name: Union[str, tuple[str, str]]