earlybird.1.3.2: fix accidental dune lower bound

Author: sim642

packages/earlybird/earlybird.1.3.2/opam

@@ -6,7 +6,7 @@ license: "MIT"
 homepage: "https://github.com/hackwaly/ocamlearlybird"
 bug-reports: "https://github.com/hackwaly/ocamlearlybird/issues"
 depends: [
-  "dune" {>= "3.7"}
+  "dune" {>= "2.8"}
   "ocaml" {>= "4.12.0"}
   "ppx_deriving" {>= "5.1" & < "5.3"}
   "ppx_deriving_yojson" {>= "3.6.1"}