docs: fix f-string in ExceptionGroup example (pythonGH-146108)

(cherry picked from commit 2c6afb9)

Co-authored-by: Bartosz Grabowski <58475557+bartosz-grabowski@users.noreply.github.com>

Author: bartosz-grabowski

Doc/tutorial/errors.rst

@@ -545,9 +545,9 @@ caught like any other exception. ::
    >>> try:
    ...     f()
    ... except Exception as e:
-   ...     print(f'caught {type(e)}: e')
+   ...     print(f'caught {type(e)}: {e}')
    ...
-   caught <class 'ExceptionGroup'>: e
+   caught <class 'ExceptionGroup'>: there were problems (2 sub-exceptions)
    >>>
 
 By using ``except*`` instead of ``except``, we can selectively