main/postmarketos-base: add replace for busybox-openrc (MR 3400)

Alpine refactored the Busybox APKBUILD which resulted into a few
renamings like busybox-initscripts to busybox-openrc.

See https://gitlab.alpinelinux.org/alpine/aports/-/commit/8b30ff10ab691ce8380423c551dd9c327a5a1f9a

main/postmarketos-base/APKBUILD

 pkgname=postmarketos-base
 pkgver=21
-pkgrel=1
+pkgrel=2
 pkgdesc="Meta package for minimal postmarketOS base"
 url="https://postmarketos.org"
 arch="noarch"
@@ -22,13 +22,14 @@ subpackages="
 	"
 options="!check"
 
-# alpine-base can be removed from here after 23.01 is out
+# alpine-base and busybox-initscripts can be removed from here after 23.01 is out
 replaces="
 	alpine-base
 	alpine-baselayout
 	alpine-baselayout-data
 	alpine-release
 	busybox-initscripts
+	busybox-openrc
 	openrc
 	sudo
 	"