Update sphinx from 4.1.0 to 4.1.1 (#45)

Author: pyup-bot

setup.cfg

@@ -35,7 +35,7 @@ fsspec = fsspec==2021.7.0
 all =
     %(fsspec)s
 docs =
-    Sphinx==4.1.0
+    Sphinx==4.1.1
     sphinx-copybutton==0.4.0
     myst-parser==0.15.1
     furo==2021.7.5b38