Upgrade rules_go (#5684)

This should help with #5672 if I'm reading the report back from
buildkite properly.

WORKSPACE

@@ -4,14 +4,14 @@ load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 http_archive(
     name = "io_bazel_rules_go",
-    sha256 = "f04d2373bcaf8aa09bccb08a98a57e721306c8f6043a2a0ee610fd6853dcde3d",
     urls = [
-        "https://storage.googleapis.com/bazel-mirror/github.com/bazelbuild/rules_go/releases/download/0.18.6/rules_go-0.18.6.tar.gz",
-        "https://github.com/bazelbuild/rules_go/releases/download/0.18.6/rules_go-0.18.6.tar.gz",
+        "https://storage.googleapis.com/bazel-mirror/github.com/bazelbuild/rules_go/releases/download/v0.20.3/rules_go-v0.20.3.tar.gz",
+        "https://github.com/bazelbuild/rules_go/releases/download/v0.20.3/rules_go-v0.20.3.tar.gz",
     ],
+    sha256 = "e88471aea3a3a4f19ec1310a55ba94772d087e9ce46e41ae38ecebe17935de7b",
 )
 
-load("@io_bazel_rules_go//go:deps.bzl", "go_register_toolchains", "go_rules_dependencies")
+load("@io_bazel_rules_go//go:deps.bzl", "go_rules_dependencies", "go_register_toolchains")
 
 go_rules_dependencies()