dev-ml/ppx_bin_prot: fix test deps, oUnit -> ounit2

Closes: https://bugs.gentoo.org/749171
Signed-off-by: Alfredo Tupone <tupone@gentoo.org>

dev-ml/ppx_bin_prot/ppx_bin_prot-0.14.0.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2022 Gentoo Authors
+# Copyright 1999-2023 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=7
@@ -28,4 +28,15 @@ RDEPEND="
 DEPEND="${RDEPEND}
 	test? (
 		dev-ml/ppx_jane
+		dev-ml/core
+		dev-ml/ounit2
+		dev-ml/core_bench
 	)"
+
+src_prepare() {
+	sed -i \
+		-e "s:oUnit:ounit2:" \
+		test/dune \
+		|| die
+	default
+}