[Bug]: Type Checking Fails with Python Union Types with `|`

[nchint]

What happened?

This bug is seen on apache-beam==2.63.0, python 3.11

Constructing a simple pipeline where a function with an additional, optional arg is a UnionType with the pipe operator results in the following exception

import apache_beam as beam


def func(x: int, y: int | None = None):
    return x


with beam.Pipeline() as p:
    (p
     | beam.Create([1])
     | beam.Map(func))

Traceback (most recent call last):
  File "/Users/chintala/Downloads/./test.py", line 9, in <module>
    (p
     ^
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/pvalue.py", line 138, in __or__
    return self.pipeline.apply(ptransform, self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/pipeline.py", line 781, in apply
    transform.type_check_inputs(pvalueish)
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/transforms/ptransform.py", line 960, in type_check_inputs
    if not typehints.is_consistent_with(bindings.get(arg, typehints.Any),
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/typehints/typehints.py", line 1317, in is_consistent_with
    return base._consistent_with_check_(sub)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/typehints/typehints.py", line 536, in _consistent_with_check_
    return any(is_consistent_with(sub, elem) for elem in self.union_types)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/typehints/typehints.py", line 536, in <genexpr>
    return any(is_consistent_with(sub, elem) for elem in self.union_types)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/chintala/builds/master/build/internal/lib/python3.11/site-packages/apache_beam/typehints/typehints.py", line 1323, in is_consistent_with
    return issubclass(sub, base)
           ^^^^^^^^^^^^^^^^^^^^^
TypeError: issubclass() arg 1 must be a class

Issue Priority

Priority: 2 (default / most bugs should be filed as P2)

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[nchint]

cc: @hjtran

[liferoad]

We need to deprecate Python 3.9 first to support |.

[Abacn]

Beam already dropped Python 3.9 support as for now.

[junaiddshaukat]

.take-issue