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/osbase/build/fsspec/BUILD.bazel b/osbase/build/fsspec/BUILD.bazel
new file mode 100644
index 0000000..b719522
--- /dev/null
+++ b/osbase/build/fsspec/BUILD.bazel
@@ -0,0 +1,25 @@
+load("@rules_proto//proto:defs.bzl", "proto_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//proto:def.bzl", "go_proto_library")
+
+proto_library(
+    name = "spec_proto",
+    srcs = ["spec.proto"],
+    visibility = ["//visibility:public"],
+)
+
+go_library(
+    name = "fsspec",
+    srcs = ["utils.go"],
+    embed = [":fsspec_go_proto"],
+    importpath = "source.monogon.dev/osbase/build/fsspec",
+    visibility = ["//visibility:public"],
+    deps = ["@org_golang_google_protobuf//encoding/prototext"],
+)
+
+go_proto_library(
+    name = "fsspec_go_proto",
+    importpath = "source.monogon.dev/osbase/build/fsspec",
+    proto = ":spec_proto",
+    visibility = ["//visibility:public"],
+)