Latest version of markdown breaks chalice deployments in github workflows

Sample Repo with workflow to reproduce the issue:

https://github.com/apfromiit/markdown-github-workflow



Workflow fails with `markdown==3.3.5`

Workflow runs successfully with `markdown==3.3.4`



## Latest version of markdown breaks chalice deployment in github actions



Workflow: https://github.com/apfromiit/markdown-github-workflow/blob/master/.github/workflows/chalice-deploy.yml



Result: https://github.com/apfromiit/markdown-github-workflow/runs/4229057005?check_suite_focus=true



Refer the workflow in `.github/workflows/` 



### Steps to reproduce:



* Fork the repo 

* Add AWS secrets to forked repo

* Modify Readme (to make some trivial changes to create dummy commit)

* git commit and push to master branch

* Check Github Actions in repo.



Github workflow fails with below logs during `chalice deploy` step.



### Logs:



```

Traceback (most recent call last):

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/cli/__init__.py", line 636, in main

    return cli(obj={})

  File "/usr/lib/python3/dist-packages/click/core.py", line 764, in __call__

    return self.main(*args, **kwargs)

  File "/usr/lib/python3/dist-packages/click/core.py", line 717, in main

    rv = self.invoke(ctx)

  File "/usr/lib/python3/dist-packages/click/core.py", line 1137, in invoke

    return _process_result(sub_ctx.command.invoke(sub_ctx))

  File "/usr/lib/python3/dist-packages/click/core.py", line 956, in invoke

    return ctx.invoke(self.callback, **ctx.params)

  File "/usr/lib/python3/dist-packages/click/core.py", line 555, in invoke

    return callback(*args, **kwargs)

  File "/usr/lib/python3/dist-packages/click/decorators.py", line 17, in new_func

    return f(get_current_context(), *args, **kwargs)

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/cli/__init__.py", line 189, in deploy

    deployed_values = d.deploy(config, chalice_stage_name=stage)

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/deploy/deployer.py", line 376, in deploy

    return self._deploy(config, chalice_stage_name)

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/deploy/deployer.py", line 382, in _deploy

    self._validate_config(config)

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/deploy/deployer.py", line 408, in _validate_config

    validate_configuration(config)

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/deploy/validate.py", line 41, in validate_configuration

    routes = config.chalice_app.routes

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/config.py", line 141, in chalice_app

    app = v()

  File "/home/runner/.local/lib/python3.8/site-packages/chalice/cli/factory.py", line 277, in load_chalice_app

    app = importlib.import_module('app')

  File "/usr/lib/python3.8/importlib/__init__.py", line 127, in import_module

    return _bootstrap._gcd_import(name[level:], package, level)

  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import

  File "<frozen importlib._bootstrap>", line 991, in _find_and_load

  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked

  File "<frozen importlib._bootstrap_external>", line 848, in exec_module

  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed

  File "/home/runner/work/markdown-github-workflow/markdown-github-workflow/app.py", line 2, in <module>

    from markdown import markdown

  File "/home/runner/.local/lib/python3.8/site-packages/markdown/__init__.py", line 29, in <module>

    from .core import Markdown, markdown, markdownFromFile  # noqa: E402

  File "/home/runner/.local/lib/python3.8/site-packages/markdown/core.py", line 26, in <module>

    from . import util

  File "/home/runner/.local/lib/python3.8/site-packages/markdown/util.py", line 88, in <module>

    INSTALLED_EXTENSIONS = metadata.entry_points(group='markdown.extensions')

TypeError: entry_points() got an unexpected keyword argument 'group'



Error: Process completed with exit code 2.

```

[]