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/build/gotoolwrap/BUILD.bazel b/build/gotoolwrap/BUILD.bazel
new file mode 100644
index 0000000..bb02dc1
--- /dev/null
+++ b/build/gotoolwrap/BUILD.bazel
@@ -0,0 +1,14 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+    name = "gotoolwrap_lib",
+    srcs = ["main.go"],
+    importpath = "source.monogon.dev/build/gotoolwrap",
+    visibility = ["//visibility:private"],
+)
+
+go_binary(
+    name = "gotoolwrap",
+    embed = [":gotoolwrap_lib"],
+    visibility = ["//visibility:public"],
+)