internal: remove obsolete pubsub/apiv1 readme

Change-Id: I679835af512783ce6f23cfaacf8b99a392e9d30c
Reviewed-on: https://code-review.googlesource.com/c/gocloud/+/44831
Reviewed-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Tyler Bui-Palsulich <tbp@google.com>
diff --git a/pubsub/apiv1/README.md b/pubsub/apiv1/README.md
deleted file mode 100644
index b5967ab..0000000
--- a/pubsub/apiv1/README.md
+++ /dev/null
@@ -1,9 +0,0 @@
-Auto-generated pubsub v1 clients
-=================================
-
-This package includes auto-generated clients for the pubsub v1 API.
-
-Use the handwritten client (in the parent directory,
-cloud.google.com/go/pubsub) in preference to this.
-
-This code is EXPERIMENTAL and subject to CHANGE AT ANY TIME.