docs: use docs/requirements.txt to install Sphinx

Author: laurent-laporte-pro

setup.py

@@ -190,9 +190,6 @@ def function_three():
             "PyTest",
             "PyTest-Cov",
             "bump2version < 1",
-            "sphinx < 2",
-            # jinja2 3.0.3 was the last version to have contextfunction that sphinx 1.x needs
-            "jinja2~=3.0.3",
             "setuptools; python_version>='3.12'",
         ]
     },

tox.ini

@@ -30,10 +30,8 @@ deps =
 
 [testenv:docs]
 basepython = python
-# jinja2 3.0.3 was the last version to have contextfunction that sphinx 1.x needs
 deps =
-    sphinx < 2
-    jinja2 == 3.0.3
+    -r docs/requirements.txt
 commands =
     sphinx-build -b html -d {envtmpdir}/doctrees docs/source/ {envtmpdir}/html
     sphinx-build -b epub -d {envtmpdir}/doctrees docs/source/ {envtmpdir}/epub