media-libs/openimageio: fix FindLibheif configuring errors

- media-libs/libheif-1.17.6 with heif_version.h multilib wrapper
  caused FindLibheif can't fetch version, use compiler preprosser
  to get correct version info.

Closes: https://bugs.gentoo.org/936472
Signed-off-by: Huang Rui <vowstar@gmail.com>
Closes: https://github.com/gentoo/gentoo/pull/37669
Signed-off-by: Andrew Ammerlaan <andrewammerlaan@gentoo.org>

media-libs/openimageio/openimageio-2.5.12.0.ebuild

@@ -126,6 +126,7 @@ PATCHES=(
 	"${FILESDIR}/${PN}-2.5.8.0-fix-unit_simd.patch"
 	"${FILESDIR}/${PN}-2.5.8.0-fix-tests.patch"
 	"${FILESDIR}/${PN}-2.5.12.0-tests-optional.patch"
+	"${FILESDIR}/${PN}-2.5.12.0-heif-find-fix.patch"
 )
 
 pkg_setup() {