main/dtbtool: fix upstream compat issues

fix depends and force a rebuild

main/dtbtool/APKBUILD

 # Contributor: Yuval Adam <_@yuv.al>
 pkgname=dtbtool
 pkgver=1.6.0
-pkgrel=3
+pkgrel=4
 pkgdesc="skales dtbtool"
 url="https://source.codeaurora.org/quic/kernel/skales/plain/dtbTool"
 arch="all"
@@ -13,7 +13,7 @@ source="
 	0003-alternate-dt-tag.patch
 	"
 options="!check"
-depends="dtc-dev python"
+depends="dtc-dev python3"
 builddir="$srcdir/build"
 
 prepare() {