Fixed #28532 -- Fixed typo in PostgreSQL field docs

Thanks Andreas Poisel for the report.

docs/ref/contrib/postgres/fields.txt

@@ -658,7 +658,7 @@ excluded; that is, ``[)``.
 .. class:: DateTimeRangeField(**options)
 
     Stores a range of timestamps. Based on a
-    :class:`~django.db.models.DateTimeField`. Represented by a ``tztsrange`` in
+    :class:`~django.db.models.DateTimeField`. Represented by a ``tstzrange`` in
     the database and a :class:`~psycopg2:psycopg2.extras.DateTimeTZRange` in
     Python.