Bump sphinx from 5.1.1 to 7.2.6 in /requirements

Bumps [sphinx](https://github.com/sphinx-doc/sphinx) from 5.1.1 to 7.2.6.
- [Release notes](https://github.com/sphinx-doc/sphinx/releases)
- [Changelog](https://github.com/sphinx-doc/sphinx/blob/master/CHANGES.rst)
- [Commits](sphinx-doc/sphinx@v5.1.1...v7.2.6)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements/dev.txt

@@ -50,7 +50,7 @@ identify==2.3.3
     # via pre-commit
 idna==3.3
     # via requests
-imagesize==1.2.0
+imagesize==1.4.1
     # via sphinx
 iniconfig==1.1.1
     # via pytest
@@ -128,13 +128,14 @@ six==1.16.0
     # via python-dateutil
 snowballstemmer==2.1.0
     # via sphinx
-sphinx==5.1.1
+sphinx==7.2.6
     # via
     #   -r docs.in
     #   pallets-sphinx-themes
     #   sphinx-issues
     #   sphinx-tabs
     #   sphinxcontrib-log-cabinet
+    #   sphinxcontrib-serializinghtml
 sphinx-issues==3.0.1
     # via -r docs.in
 sphinx-tabs==3.4.1
@@ -151,7 +152,7 @@ sphinxcontrib-log-cabinet==1.0.1
     # via -r docs.in
 sphinxcontrib-qthelp==1.0.3
     # via sphinx
-sphinxcontrib-serializinghtml==1.1.5
+sphinxcontrib-serializinghtml==1.1.9
     # via sphinx
 tomli==2.0.1
     # via pep517

requirements/docs.txt

@@ -18,7 +18,7 @@ docutils==0.18.1
     #   sphinx-tabs
 idna==3.3
     # via requests
-imagesize==1.2.0
+imagesize==1.4.1
     # via sphinx
 jinja2==3.0.2
     # via sphinx
@@ -42,13 +42,14 @@ requests==2.26.0
     # via sphinx
 snowballstemmer==2.1.0
     # via sphinx
-sphinx==5.1.1
+sphinx==7.2.6
     # via
     #   -r docs.in
     #   pallets-sphinx-themes
     #   sphinx-issues
     #   sphinx-tabs
     #   sphinxcontrib-log-cabinet
+    #   sphinxcontrib-serializinghtml
 sphinx-issues==3.0.1
     # via -r docs.in
 sphinx-tabs==3.4.1
@@ -65,7 +66,7 @@ sphinxcontrib-log-cabinet==1.0.1
     # via -r docs.in
 sphinxcontrib-qthelp==1.0.3
     # via sphinx
-sphinxcontrib-serializinghtml==1.1.5
+sphinxcontrib-serializinghtml==1.1.9
     # via sphinx
 urllib3==1.26.7
     # via requests