Add Sphinx 7 support (#1464)

* Allow Sphinx 7

* Also build theme docs with Sphinx 7

* Add more tests cases on tox.ini

* Increase the Sphinx version for the docs

---------

Co-authored-by: Manuel Kaufmann <humitos@gmail.com>

docs/requirements.txt

@@ -1 +1 @@
-sphinx>=6.1,<6.2
+sphinx>=7.1,<7.2

setup.cfg

@@ -45,7 +45,7 @@ zip_safe = False
 packages = sphinx_rtd_theme
 python_requires = >=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,!=3.5.*
 install_requires = 
-	sphinx >=1.6,<7
+	sphinx >=1.6,<8
 	docutils <0.19
 	sphinxcontrib-jquery >=4,<5
 tests_require = 

tox.ini

@@ -6,9 +6,9 @@ envlist =
     # Python 3.10 working from Sphinx 4.2 and up
     py{310}-sphinx{42,43,44,45,50,51,52,53,latest}{-html4,-html5}{-qa,}
     # Sphinx 6+ has simplified docutils and Python support
-    py{38,39,10}-sphinx{60}{-html5,}{-qa,}
+    py{38,39,10}-sphinx{60,61,70,71}{-html5,}{-qa,}
     # Python 3.11 working from Sphinx 5.3 and up
-    py{311}-sphinx{53,60,latest}{html5}{-qa,}
+    py{311}-sphinx{53,60,61,70,71,latest}{html5}{-qa,}
 
 [testenv]
 setenv =
@@ -41,6 +41,9 @@ deps =
     sphinx52: Sphinx>=5.2,<5.3
     sphinx53: Sphinx>=5.3,<5.4
     sphinx60: Sphinx>=6.0,<6.1
+    sphinx61: Sphinx>=6.1,<6.2
+    sphinx70: Sphinx>=7.0,<7.1
+    sphinx71: Sphinx>=7.1,<7.2
     # All these Sphinx versions actually break since docutils 0.18, so we need to add this upper bound
     # Projects using these Sphinx versions will have to do the same
     # See: https://github.com/readthedocs/sphinx_rtd_theme/pull/1304