Merge pull request ocaml#22779 from raphael-proust/bechamel-ocaml5

bechamel.0.[12].0 are not compatible with ocaml5

Author: kit-ty-kate

packages/bechamel/bechamel.0.1.0/opam

@@ -18,7 +18,7 @@ build: [
 ]
 
 depends: [
-  "ocaml"      {>= "4.08.0"}
+  "ocaml"      {>= "4.08.0" & < "5.0"}
   "dune"       {>= "2.0.0"}
   "fmt"
   "base-bytes"

packages/bechamel/bechamel.0.2.0/opam

@@ -17,7 +17,7 @@ build: [
 ]
 
 depends: [
-  "ocaml"      {>= "4.08.0"}
+  "ocaml"      {>= "4.08.0" & < "5.0"}
   "dune"       {>= "2.0.0"}
   "fmt"        {>= "0.9.0"}
   "base-bytes"