Revert "WIP"

This reverts commit 1e773c5.

Author: vouillon

tools/ci_setup.ml

@@ -304,7 +304,7 @@ let pin_packages () = sync_exec pin (StringSet.elements do_pin)
 
 let install_others others =
   let others = StringSet.elements (StringSet.diff others omitted_others) in
-  ignore (Sys.command ("opam install -y sedlex.3.4 " ^ String.concat " " others))
+  ignore (Sys.command ("opam install -y " ^ String.concat " " others))
 
 let clone ?branch ?(depth = 1) nm src =
   exec_async