treewide: remove direct access to external/

This prepares the repositoriy to be compatible with the flag
--nolegacy_external_runfiles. This reduces runfiles & sandbox creation
 times.

Change-Id: I06720be4a3c873d68d8278dcb24271ed874f7134
Reviewed-on: https://review.monogon.dev/c/monogon/+/2747
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/build/toolbase/gotoolchain/BUILD.bazel b/build/toolbase/gotoolchain/BUILD.bazel
index 42dc877..1842398 100644
--- a/build/toolbase/gotoolchain/BUILD.bazel
+++ b/build/toolbase/gotoolchain/BUILD.bazel
@@ -6,7 +6,7 @@
     importpath = "source.monogon.dev/build/toolbase/gotoolchain",
     visibility = ["//visibility:public"],
     deps = [
-        "@io_bazel_rules_go//go/tools/bazel:go_default_library",
+        "@io_bazel_rules_go//go/runfiles:go_default_library",
     ],
 )