Revert update to _ngettext type hint and docstring.

It sometimes gets called with a float (and seems to work as expected), but it looks like it officially only supports an int, so leave it as it was.

Author: nuztalgia

src/humanize/i18n.py

@@ -107,14 +107,14 @@ def _pgettext(msgctxt: str, message: str) -> str:
         return message if translation == key else translation
 
 
-def _ngettext(message: str, plural: str, num: int | float) -> str:
+def _ngettext(message: str, plural: str, num: int) -> str:
     """Plural version of _gettext.
 
     Args:
         message (str): Singular text to translate.
         plural (str): Plural text to translate.
-        num (int or float): The number (e.g. item count) to determine translation for
-            the respective grammatical number.
+        num (int): The number (e.g. item count) to determine translation for the
+            respective grammatical number.
 
     Returns:
         str: Translated text.