Cleanup internal type annotation variables

`_format.py` had a few internal variables to make type annotations shorter to write. However, these can cause issues with sphinx nitpick. Even though the variables removed in this commit aren't causing a build failure, removing them is a good precaution.

Author: sirosen

jsonschema/_format.py

@@ -9,9 +9,6 @@
 
 from jsonschema.exceptions import FormatError
 
-_FormatCheckerFunc = typing.Callable[[typing.Any], bool]
-_CheckerRaises = typing.Union[Exception, typing.Tuple[Exception, ...]]
-
 
 class FormatChecker(object):
  """
@@ -38,7 +35,10 @@ class FormatChecker(object):
 
  checkers: dict[
  str,
- tuple[_FormatCheckerFunc, _CheckerRaises],
+ tuple[
+ typing.Callable[[typing.Any], bool],
+ Exception | tuple[Exception, ...],
+ ],
  ] = {}
 
  def __init__(self, formats=None):