Support python 3.13

[mattmart3]

Using doorstop from pre-commit hooks with pre-commit v4.0.1 I encountered the following issue:

check for doorstop errors................................................Failed
- hook id: check-doorstop-errors
- duration: 0.24s
- exit code: 1

Traceback (most recent call last):
  File "/home/user/.cache/pre-commit/repobelzyq3i/py_env-python3.13/bin/doorstop", line 5, in <module>
    from doorstop.cli.main import main
  File "/home/user/.cache/pre-commit/repobelzyq3i/py_env-python3.13/lib/python3.13/site-packages/doorstop/__init__.py", line 8, in <module>
    from doorstop.core import (
    ...<11 lines>...
    )
  File "/home/user/.cache/pre-commit/repobelzyq3i/py_env-python3.13/lib/python3.13/site-packages/doorstop/core/publisher.py", line 10, in <module>
    from doorstop.core.publishers.html import HtmlPublisher
  File "/home/user/.cache/pre-commit/repobelzyq3i/py_env-python3.13/lib/python3.13/site-packages/doorstop/core/publishers/html.py", line 9, in <module>
    import bottle
  File "/home/user/.cache/pre-commit/repobelzyq3i/py_env-python3.13/bin/bottle.py", line 38, in <module>
    import base64, cgi, email.utils, functools, hmac, itertools, mimetypes,\
            os, re, subprocess, sys, tempfile, threading, time, warnings, hashlib
ModuleNotFoundError: No module named 'cgi'

It looks like that the cgi module is no longer supported with python3.13, which is the version used by the recent pre-commit.

I haven't checked it in details but it looks like upstream doorstop already supports python3.13, thus pulling from upstream may fix this.