Fix code-block in zoneinfo (GH-20201)
```
Warning, treated as error:
/tmp/code/Doc/library/zoneinfo.rst:303:Error in "code-block" directive:
1 argument(s) required, 0 supplied.
.. code-block::
>>> a = ZoneInfo("Europe/Berlin")
>>> b = pickle.loads(europe_berlin_pkl)
>>> a is b
True
```diff --git a/Doc/library/zoneinfo.rst b/Doc/library/zoneinfo.rst
index 1b6f2e7..3a4c12a 100644
--- a/Doc/library/zoneinfo.rst
+++ b/Doc/library/zoneinfo.rst
@@ -300,7 +300,7 @@
constructed from ``ZoneInfo("Europe/Berlin")``, one would expect the
following behavior:
- .. code-block::
+ .. code-block:: pycon
>>> a = ZoneInfo("Europe/Berlin")
>>> b = pickle.loads(europe_berlin_pkl)
@@ -314,7 +314,7 @@
constructed from ``ZoneInfo.no_cache("Europe/Berlin")``, one would expect
the following behavior:
- .. code-block::
+ .. code-block:: pycon
>>> a = ZoneInfo("Europe/Berlin")
>>> b = pickle.loads(europe_berlin_pkl_nc)