Merge pull request ocaml#22716 from hannesm/dream-httpaf-ocaml5

dream-httpaf is not compatible with ocaml5:

Author: kit-ty-kate

packages/dream-httpaf/dream-httpaf.1.0.0~alpha1/opam

@@ -18,7 +18,7 @@ depends: [
   "lwt"
   "lwt_ppx" {>= "1.2.2"}
   "lwt_ssl"
-  "ocaml" {>= "4.08.0"}
+  "ocaml" {>= "4.08.0" & < "5.0"}
   "ssl" {>= "0.5.8"}  # Ssl.get_negotiated_alpn_protocol.
 
   # Currently vendored.