Increase ocaml version to 4.14.2

Since we require GT>=0.5.2 that requires ocaml>=4.13, we already require
ocaml>=4.13 (actually >=4.14.2 due to ppx testing libs). So, let's do it
explicitly

Signed-off-by: Eridan Domoratskiy <[email protected]>
Coauthored-by: Dmitrii Kosarev a.k.a. Kakadu <[email protected]>

Author: ProgMiner

OCanren-ppx.opam

@@ -33,7 +33,7 @@ homepage: "https://github.com/PLTools/OCanren"
 bug-reports: "https://github.com/PLTools/OCanren/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.10"}
+  "ocaml" {>= "4.14.2"}
   "dune-configurator"
   "ppxlib" {>= "0.26.0" & <= "0.28.0"}
   "ppx_inline_test_nobase"

OCanren.opam

@@ -24,7 +24,7 @@ homepage: "https://github.com/PLTools/OCanren"
 bug-reports: "https://github.com/PLTools/OCanren/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.10"}
+  "ocaml" {>= "4.14.2"}
   "dune-configurator"
   "ocamlfind"
   "camlp5"

dune-project

@@ -19,7 +19,7 @@
   "The family of miniKanren derivatives has many implementations. This\none is typed embedding to OCaml. The original implementation for\nthis is in scheme and can be found at https://github.com/michaelballantyne/faster-miniKanren .\n\nFeatures:\n1) disequality constraints\n2) relational standard library: lists, nats\n")
  (depends
   (ocaml
-   (>= 4.10))
+   (>= 4.14.2))
   dune-configurator
   ocamlfind
   camlp5
@@ -53,7 +53,7 @@
   "PPX rewriters for writing relational programs more conveniently.\n\n1) `ppx_fresh` -- a clone of original miniKanren syntax\n\n  fresh (x...) goal\n\nexpands into\n\n  Fresh.numeral (fun x ... -> goal)\n\n2) `ppx_distrib` for easier generation of type-safe wrappers: distrib functor, etc...\n\n  [%%distrib\n    type t = fully_abstract_typee\n    type ground = ...\n  ]\n\n3) `ppx_repr` for test. Expands `REPR(expr)` to `(string_of_expr expr, expr)`\n")
  (depends
   (ocaml
-   (>= 4.10))
+   (>= 4.14.2))
   dune-configurator
   (ppxlib
    (and