build: fix bazel version (#19553)

Executing tests on MacOS Catalina runs into issues with bazel 3.0.0.
Bazel will use the version specified in the .bazelversion file and hence
no matter what is installed, if 3.0.0 is available that will run.

d4d12a9 changed WORKSPACE and .bazelversion from 3.1.0 to 3.0.0 which
looks to have introduced this issue.

Changing back to 3.1.0 fixes tests on Catalina

Author: andy9775

.bazelversion

@@ -1 +1 @@
-3.0.0
+3.1.0

WORKSPACE

@@ -29,7 +29,7 @@ http_archive(
 load("@build_bazel_rules_nodejs//:index.bzl", "check_bazel_version", "node_repositories", "yarn_install")
 
 # The minimum bazel version to use with this repo is v3.1.0.
-check_bazel_version("3.0.0")
+check_bazel_version("3.1.0")
 
 node_repositories(
     node_repositories = {