treewide: move build helper to more fitting places

Change-Id: I3d0cfe9283222d403ae369ec9db09201ad511e15
Reviewed-on: https://review.monogon.dev/c/monogon/+/3327
Reviewed-by: Serge Bazanski <serge@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/node/core/update/BUILD.bazel b/metropolis/node/core/update/BUILD.bazel
index 30ca20b..f60ba40 100644
--- a/metropolis/node/core/update/BUILD.bazel
+++ b/metropolis/node/core/update/BUILD.bazel
@@ -9,9 +9,9 @@
     importpath = "source.monogon.dev/metropolis/node/core/update",
     visibility = ["//visibility:public"],
     deps = [
-        "//metropolis/node/build/mkimage/osimage",
         "//metropolis/node/core/abloader/spec",
         "//osbase/blockdev",
+        "//osbase/build/mkimage/osimage",
         "//osbase/efivarfs",
         "//osbase/gpt",
         "//osbase/kexec",