Revert Sphinx version to 8.1.3

Signed-off-by: tdruez <tdruez@nexb.com>

Author: tdruez

setup.cfg

@@ -118,7 +118,7 @@ dev =
     # Debug
     django-debug-toolbar==5.0.1
     # Documentation
-    Sphinx==8.2.3
+    Sphinx==8.1.3
     sphinx-rtd-theme==3.0.2
     sphinx-rtd-dark-mode==1.3.0
     sphinxcontrib-django==2.5