osbase/logtree.LeveledLogger -> go/logging.Leveled

This factors out the common leveled logger interface out of the logtree.
We want to use the same interface outside of logtree/supervisor usage
within the resolver code, which will be exposed to clients.

Change-Id: I299e76d91e8cefddf8f36f1e58432418c4694df2
Reviewed-on: https://review.monogon.dev/c/monogon/+/3411
Reviewed-by: Tim Windelschmidt <tim@monogon.tech>
Tested-by: Jenkins CI
diff --git a/osbase/supervisor/BUILD.bazel b/osbase/supervisor/BUILD.bazel
index b6b4861..9dfda5a 100644
--- a/osbase/supervisor/BUILD.bazel
+++ b/osbase/supervisor/BUILD.bazel
@@ -15,6 +15,7 @@
     # TODO(#189): move supervisor to //go
     visibility = ["//visibility:public"],
     deps = [
+        "//go/logging",
         "//osbase/logtree",
         "@com_github_cenkalti_backoff_v4//:backoff",
         "@com_github_prometheus_client_golang//prometheus",