Drop older versions of sphinx (for the moment maybe?)

Author: jonascj

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    {py39,py310,py311,py312,py313,pypy3}-sphinx{201,212,222,231,244,300,321,latest}
+    {py39,py310,py311,py312,py313,pypy3}-sphinx{321,400}
 
 [testenv]
 minversion = 3.15.0
@@ -15,14 +15,8 @@ deps =
     setuptools
     build
     sphinx-rtd-theme==0.1.6
-    sphinx185: sphinx==1.8.5
-    sphinx201: sphinx==2.0.1
-    sphinx212: sphinx==2.1.2
-    sphinx222: sphinx==2.2.2
-    sphinx231: sphinx==2.3.1
-    sphinx244: sphinx==2.4.4
-    sphinx300: sphinx==3.0.0
     sphinx321: sphinx==3.2.1
+    sphinx400: sphinx==4.0.0
     sphinxlatest: sphinx
     wheel