Merge pull request ocaml#22829 from mseri/fix-vector

vector3 0.2.1 is not compatible with ocaml5

Author: kit-ty-kate

packages/vector3/vector3.0.2.1/opam

@@ -15,7 +15,7 @@ remove: [
   ["ocamlfind" "remove" "vector3"]
 ]
 depends: [
-  "ocaml"
+  "ocaml" {< "5.0"}
   "ocamlfind"
   "ocamlbuild" {build}
 ]