gh-106318: Fix typo in the str.isdigit() docs

Author: adorilson

Doc/library/stdtypes.rst

@@ -2278,7 +2278,7 @@ expression support in the :mod:`re` module).
       >>> '²'.isdecimal(), '²'.isdigit(),  '²'.isnumeric()
       (False, True, True)
 
-   See also :meth:`isdecimal` and :meth:`isnumeric`. Digital characters are a
+   See also :meth:`isdecimal` and :meth:`isnumeric`. Digit characters are a
    superset of decimal characters.