add missing colon (#13640)

Author: jakkdl

src/_pytest/raises.py

@@ -559,7 +559,7 @@ class RaisesExc(AbstractRaises[BaseExcT_co_default]):
         The type is checked with :func:`isinstance`, and does not need to be an exact match.
         If that is wanted you can use the ``check`` parameter.
 
-    :kwparam str | Pattern[str] match
+    :kwparam str | Pattern[str] match:
         A regex to match.
 
     :kwparam Callable[[BaseException], bool] check: