remove uneeded dependency

Signed-off-by: Avi Shinnar <shinnar@us.ibm.com>

Author: shinnar

Formal_ML.opam

@@ -13,7 +13,6 @@ depends: [
   "rocq-stdlib"
   "rocq-mathcomp-ssreflect"
   "coq-coquelicot"
-  "coq-ext-lib" {<= "1.0.0"}
   "coq-coq2html" {with-doc}
 ]
 build: [[make]