Update go dependencies

vendor/github.com/grpc-ecosystem/grpc-gateway/BUILD

@@ -0,0 +1,25 @@
+load("@bazel_gazelle//:def.bzl", "gazelle")
+load("@com_github_bazelbuild_buildtools//buildifier:def.bzl", "buildifier")
+
+buildifier(
+    name = "buildifier",
+)
+
+buildifier(
+    name = "buildifier_check",
+    mode = "check",
+)
+
+# gazelle:exclude third_party
+# gazelle:exclude vendor
+# gazelle:prefix github.com/grpc-ecosystem/grpc-gateway
+
+gazelle(name = "gazelle")
+
+package_group(
+    name = "generators",
+    packages = [
+        "//protoc-gen-grpc-gateway/...",
+        "//protoc-gen-swagger/...",
+    ],
+)