Update to gazelle 0.12.0 and run hack/update-bazel.sh

vendor/github.com/coreos/etcd/clientv3/BUILD

@@ -23,6 +23,7 @@ go_library(
         "txn.go",
         "watch.go",
     ],
+    importmap = "vendor/github.com/coreos/etcd/clientv3",
     importpath = "github.com/coreos/etcd/clientv3",
     visibility = ["//visibility:public"],
     deps = [

vendor/github.com/coreos/etcd/clientv3/concurrency/BUILD

@@ -10,6 +10,7 @@ go_library(
         "session.go",
         "stm.go",
     ],
+    importmap = "vendor/github.com/coreos/etcd/clientv3/concurrency",
     importpath = "github.com/coreos/etcd/clientv3/concurrency",
     visibility = ["//visibility:public"],
     deps = [

vendor/github.com/coreos/etcd/clientv3/namespace/BUILD

@@ -9,6 +9,7 @@ go_library(
         "util.go",
         "watch.go",
     ],
+    importmap = "vendor/github.com/coreos/etcd/clientv3/namespace",
     importpath = "github.com/coreos/etcd/clientv3/namespace",
     visibility = ["//visibility:public"],
     deps = [

vendor/github.com/coreos/etcd/clientv3/naming/BUILD

@@ -6,6 +6,7 @@ go_library(
         "doc.go",
         "grpc.go",
     ],
+    importmap = "vendor/github.com/coreos/etcd/clientv3/naming",
     importpath = "github.com/coreos/etcd/clientv3/naming",
     visibility = ["//visibility:public"],
     deps = [