Bump sphinx from 3.4.3 to 4.4.0

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 3.4.3 to 4.4.0.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/4.x/CHANGES)
- [Commits](https://github.com/sphinx-doc/sphinx/compare/v3.4.3...v4.4.0)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -5,8 +5,8 @@
 #    pipenv lock --requirements
 #
 
--i https://pypi.python.org/simple
---extra-index-url https://www.piwheels.org/simple
+-i https://pypi.python.org/simple/
+--extra-index-url https://www.piwheels.org/simple/
 aioredis==1.3.1
 arrow==1.2.2; python_version >= '3.6'
 asgiref==3.5.0; python_version >= '3.7'
@@ -14,7 +14,6 @@ async-timeout==4.0.2; python_version >= '3.6'
 attrs==21.4.0; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'
 autobahn==22.2.2; python_version >= '3.7'
 automat==20.2.0
-backports.zoneinfo==0.2.1; python_version < '3.9'
 blessed==1.19.1; python_version >= '2.7'
 certifi==2021.10.8
 cffi==1.15.0
@@ -47,7 +46,6 @@ hyperlink==21.0.0
 idna==3.3; python_version >= '3.5'
 imap-tools==0.52.0
 img2pdf==0.4.3
-importlib-resources==5.4.0; python_version < '3.9'
 incremental==21.3.0
 inotify-simple==1.3.5; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'
 inotifyrecursive==0.3.5
@@ -105,5 +103,4 @@ wcwidth==0.2.5
 websockets==10.2
 whitenoise==6.0.0
 whoosh==2.7.4
-zipp==3.7.0; python_version < '3.10'
 zope.interface==5.4.0; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'