Update packages/xtmpl_ppx/xtmpl_ppx.1.1.0/opam

Author: mseri

packages/xtmpl_ppx/xtmpl_ppx.1.1.0/opam

@@ -7,6 +7,7 @@ homepage: "https://www.good-eris.net/xtmpl/"
 doc: "https://www.good-eris.net/xtmpl/doc.html"
 bug-reports: "https://framagit.org/zoggy/xtmpl/issues"
 depends: [
+  "ocaml" {< "5.4~"}
   "dune" {>= "3.19"}
   "xtmpl" {= version}
   "ppxlib" {>= "0.23.0"}