Website build deprecation warnings

[nicowilliams]

: ; (source venv/bin/activate && (cd ../docs && pipenv install && pipenv run python build_website.py))
Installing dependencies from Pipfile.lock (62a1ce)…
Ignoring importlib-metadata: markers 'python_version < "3.8"' don't match your environment
Ignoring typing-extensions: markers 'python_version < "3.8"' don't match your environment
  🐍   ▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉ 8/8 — 00:00:09
/home/nico/ws/jq/docs/build_website.py:29: DeprecationWarning: 'contextfunction' is renamed to 'pass_context', the old name will be removed in Jinja 3.1.
  env.globals['unique_id'] = contextfunction(
/home/nico/ws/jq/docs/build_website.py:26: DeprecationWarning: 'jinja2.Markup' is deprecated and will be removed in Jinja 3.1. Import 'markupsafe.Markup' instead.
  env.filters['markdownify'] = lambda input: Markup(markdown(input))
/home/nico/ws/jq/docs/build_website.py:27: DeprecationWarning: 'jinja2.Markup' is deprecated and will be removed in Jinja 3.1. Import 'markupsafe.Markup' instead.
  env.filters['no_paragraph'] = lambda input: Markup(re.sub(r"</?p>", '', input))

[itchyny]

#2628 will resolve the issue.