Bump sphinx from 4.0.2 to 4.1.2

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 4.0.2 to 4.1.2.
- [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/v4.0.2...v4.1.2)

---
updated-dependencies:
- dependency-name: sphinx
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements/dev.txt

@@ -98,7 +98,7 @@ six==1.16.0
     #   virtualenv
 snowballstemmer==2.1.0
     # via sphinx
-sphinx==4.0.2
+sphinx==4.1.2
     # via
     #   -r requirements/docs.in
     #   pallets-sphinx-themes
@@ -113,7 +113,7 @@ sphinxcontrib-applehelp==1.0.2
     # via sphinx
 sphinxcontrib-devhelp==1.0.2
     # via sphinx
-sphinxcontrib-htmlhelp==1.0.3
+sphinxcontrib-htmlhelp==2.0.0
     # via sphinx
 sphinxcontrib-jsmath==1.0.1
     # via sphinx
@@ -121,7 +121,7 @@ sphinxcontrib-log-cabinet==1.0.1
     # via -r requirements/docs.in
 sphinxcontrib-qthelp==1.0.3
     # via sphinx
-sphinxcontrib-serializinghtml==1.1.4
+sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
 toml==0.10.2
     # via

requirements/docs.txt

@@ -42,7 +42,7 @@ requests==2.25.1
     # via sphinx
 snowballstemmer==2.1.0
     # via sphinx
-sphinx==4.0.2
+sphinx==4.1.2
     # via
     #   -r requirements/docs.in
     #   pallets-sphinx-themes
@@ -57,7 +57,7 @@ sphinxcontrib-applehelp==1.0.2
     # via sphinx
 sphinxcontrib-devhelp==1.0.2
     # via sphinx
-sphinxcontrib-htmlhelp==1.0.3
+sphinxcontrib-htmlhelp==2.0.0
     # via sphinx
 sphinxcontrib-jsmath==1.0.1
     # via sphinx
@@ -65,7 +65,7 @@ sphinxcontrib-log-cabinet==1.0.1
     # via -r requirements/docs.in
 sphinxcontrib-qthelp==1.0.3
     # via sphinx
-sphinxcontrib-serializinghtml==1.1.4
+sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
 urllib3==1.26.5
     # via requests