ast docs: Fix incorrect link on keyword (python#108728)

In two places, Sphinx was erroneously adding links to the `keyword` module instead of the `ast.keyword` class

Doc/library/ast.rst

@@ -585,7 +585,7 @@ Expressions
    :class:`Name` or :class:`Attribute` object. Of the arguments:
 
    * ``args`` holds a list of the arguments passed by position.
-   * ``keywords`` holds a list of :class:`keyword` objects representing
+   * ``keywords`` holds a list of :class:`.keyword` objects representing
      arguments passed by keyword.
 
    When creating a ``Call`` node, ``args`` and ``keywords`` are required, but
@@ -2024,7 +2024,7 @@ Function and class definitions
 
    * ``name`` is a raw string for the class name
    * ``bases`` is a list of nodes for explicitly specified base classes.
-   * ``keywords`` is a list of :class:`keyword` nodes, principally for 'metaclass'.
+   * ``keywords`` is a list of :class:`.keyword` nodes, principally for 'metaclass'.
      Other keywords will be passed to the metaclass, as per `PEP-3115
      <https://peps.python.org/pep-3115/>`_.
    * ``body`` is a list of nodes representing the code within the class