Update opam

Author: dkalinichenko-js

packages/ocaml-variants/ocaml-variants.5.2.0+ox/opam

@@ -111,7 +111,7 @@ conflicts: [
   "ctypes" {!= "0.23.0+ox"}
   "ctypes-foreign" {!= "0.23.0+ox"}
   "dot-merlin-reader" {!= "5.2.1-502+ox"}
-  "dune" {> "3.20.2"}
+  "dune" {<= "3.20.2"}
   "gen_js_api" {!= "1.1.2+ox"}
   "js_of_ocaml" {!= "6.0.1+ox"}
   "js_of_ocaml-compiler" {!= "6.0.1+ox"}