Fix dual dune requirement

Author: dlesbre

dune-project

@@ -54,8 +54,7 @@
    (>= 4.14))
   (zarith
    (>= "1.13"))
-  (dune
-   (>= "2.0"))
+  dune
   (qcheck-core
    (and
     (>= "0.21.2")

patricia-tree.opam

@@ -16,7 +16,7 @@ bug-reports:
 depends: [
   "ocaml" {>= "4.14"}
   "zarith" {>= "1.13"}
-  "dune" {>= "2.7" & >= "2.0"}
+  "dune" {>= "2.7"}
   "qcheck-core" {>= "0.21.2" & with-test}
   "ppx_inline_test" {>= "v0.16.0" & with-test}
   "odoc" {with-doc}