testing/ocaml*: change ocaml-cppo-dev to ocaml-cppo

in makedepends, to workaround a problem on ppc64le
only (other architectures do not encounter this)

>>> utop: Analyzing dependencies...
ERROR: unable to select packages:
  ocaml4-impl:Ocamlbuild_plugin:35e029bf41b01449484051712a0cf481 (no such package):
    required by: ocaml-cppo-ocamlbuild-1.6.9-r4[ocaml4-impl:Ocamlbuild_plugin:35e029bf41b01449484051712a0cf481]
  .makedepends-utop-20240324.012502:
    masked in: cache
    satisfies: world[.makedepends-utop=20240324.012502]
>>> ERROR: utop: builddeps failed

ocaml-merlin-extend, utop, and reason do not seem to depend on the
cppo ocamlbuild plugin, so using -dev was probably not intended

testing/ocaml-merlin-extend/APKBUILD

@@ -13,7 +13,7 @@ makedepends="
 	dune
 	ocaml
 	ocaml-compiler-libs
-	ocaml-cppo-dev
+	ocaml-cppo
 	ocaml-findlib
 	"
 options="!check"  # no tests provided

testing/reason/APKBUILD

@@ -13,7 +13,7 @@ makedepends="
 	dune
 	ocaml
 	ocaml-compiler-libs
-	ocaml-cppo-dev
+	ocaml-cppo
 	ocaml-findlib-dev
 	ocaml-fix-dev
 	ocaml-menhir

testing/utop/APKBUILD

@@ -18,7 +18,7 @@ makedepends="
 	ocaml-camomile-dev
 	ocaml-charinfo_width-dev
 	ocaml-compiler-libs
-	ocaml-cppo-dev
+	ocaml-cppo
 	ocaml-csexp-dev
 	ocaml-findlib-dev
 	ocaml-lambda-term-dev