Support Python 3.12 feature: PEP 613 Explicit Type Alias

[Garrett-R]

In PEP 613, this is valid Python:

type NumDingleberries = int

but running the latest YAPF (0.43.0) gives an error:

Traceback (most recent call last):
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/yapflib/yapf_api.py", line 198, in FormatCode
    tree = pytree_utils.ParseCodeToTree(unformatted_source)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/pytree/pytree_utils.py", line 113, in ParseCodeToTree
    tree = parser_driver.parse_string(code, debug=False)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf_third_party/_ylib2to3/pgen2/driver.py", line 187, in parse_string
    return self.parse_tokens(tokens, debug)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf_third_party/_ylib2to3/pgen2/driver.py", line 156, in parse_tokens
    if p.addtoken(type, value, (prefix, start)):
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf_third_party/_ylib2to3/pgen2/parse.py", line 230, in addtoken
    return self._addtoken(ilabel, type, value, context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf_third_party/_ylib2to3/pgen2/parse.py", line 313, in _addtoken
    raise ParseError('bad input', type, value, context)
yapf_third_party._ylib2to3.pgen2.parse.ParseError: bad input: type=1, value='NumDingleberries', context=(' ', (1, 5))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/__init__.py", line 238, in _FormatFile
    reformatted_code, encoding, has_change = yapf_api.FormatFile(
                                             ^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/yapflib/yapf_api.py", line 88, in FormatFile
    reformatted_source, changed = FormatCode(
                                  ^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/yapflib/yapf_api.py", line 201, in FormatCode
    raise errors.YapfError(errors.FormatErrorMsg(e))
                           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/yapflib/errors.py", line 37, in FormatErrorMsg
    return '{}:{}:{}: {}'.format(e.args[1][0], e.args[1][1], e.args[1][2], e.msg)
                                 ~~~~~~^^^
IndexError: tuple index out of range

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/garrett/.virtualenvs/tester/bin/yapf", line 8, in <module>
    sys.exit(run_main())
             ^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/__init__.py", line 377, in run_main
    sys.exit(main(sys.argv))
             ^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/__init__.py", line 136, in main
    changed = FormatFiles(
              ^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/__init__.py", line 214, in FormatFiles
    changed |= _FormatFile(filename, lines, style_config, no_local_style,
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/__init__.py", line 248, in _FormatFile
    raise errors.YapfError(errors.FormatErrorMsg(e))
                           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/garrett/.virtualenvs/tester/lib/python3.12/site-packages/yapf/yapflib/errors.py", line 37, in FormatErrorMsg
    return '{}:{}:{}: {}'.format(e.args[1][0], e.args[1][1], e.args[1][2], e.msg)
                                 ~~~~~~^^^
IndexError: tuple index out of range

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Note: similar to #1170 which also adds support for a Python 3.12 feature