internal/rosa/busybox: link /usr/bin/env

This is required by many scripts which uses bash but still pretends to be portable.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/busybox.go

@@ -325,6 +325,8 @@ mkdir -pv /work/system/bin/
 busybox --install -s /work/system/bin/
 cp -v busybox /work/system/bin/
 ln -vs ../system/bin/hush /work/bin/sh
+mkdir -vp /work/usr/bin/
+ln -vs ../../system/bin/busybox /work/usr/bin/env
 `, pkg.Path(AbsUsrSrc.Append("busybox"), true, pkg.NewHTTPGetTar(
 		&http.Client{Transport: &http.Transport{
 			// busybox website is really slow to respond