protobuf: add //:go_features_proto Bazel alias (#20419)

Users who use Protobuf via Bazel currently have no way of specifying a
dependency on the well-known go_features.proto.

For golang/protobuf#1679

PiperOrigin-RevId: 728991839

Co-authored-by: Protobuf Team Bot <protobuf-github-bot@google.com>

BUILD.bazel

@@ -468,6 +468,16 @@ alias(
     visibility = ["//visibility:public"],
 )
 
+################################################################################
+# Go support
+################################################################################
+
+alias(
+    name = "go_features_proto",
+    actual = "//go:go_features_proto",  # proto_library
+    visibility = ["//visibility:public"],
+)
+
 ################################################################################
 # Test protos
 ################################################################################

go/BUILD.bazel

@@ -10,8 +10,6 @@ proto_library(
     name = "go_features_proto",
     srcs = ["google/protobuf/go_features.proto"],
     strip_import_prefix = "/go",
-    visibility = [
-        "//pkg:__pkg__",
-    ],
+    visibility = ["//:__subpackages__"],
     deps = ["//:descriptor_proto"],
 )