Remove authorizing asset store

Authorization should be handled by the fetch/push servers, not the asset store.

Author: tomcoldrick-ct

pkg/storage/BUILD.bazel

@@ -7,7 +7,6 @@ go_library(
         "asset.go",
         "asset_reference.go",
         "asset_store.go",
-        "authorizing_asset_store.go",
         "blob_access_asset_store.go",
         "digest.go",
     ],
@@ -35,7 +34,6 @@ go_test(
     srcs = [
         "action_cache_asset_store_test.go",
         "asset_reference_test.go",
-        "authorizing_asset_store_test.go",
         "blob_access_asset_store_test.go",
     ],
     deps = [