update strict-sphinx to v7 (#36075)

Author: kristapratico

eng/tox/tox.ini

@@ -352,7 +352,7 @@ setenv =
   PROXY_URL=http://localhost:5023
 deps =
   {[base]deps}
-  sphinx==6.2.1
+  sphinx==7.3.7
   sphinx_rtd_theme==1.3.0
   myst_parser==2.0.0
   sphinxcontrib-jquery==4.1