Remove Buildkite unit/lint tests from expeditor config

.expeditor/config.yml

@@ -44,8 +44,3 @@ subscriptions:
     actions:
       - built_in:rollover_changelog
       - built_in:publish_rubygems
-
-pipelines:
-  - verify:
-      description: Pull Request validation tests
-      public: true

.github/workflows/allchecks.yml

@@ -0,0 +1,19 @@
+name: All checks pass
+on:
+  pull_request:
+    types: [ opened, synchronize, reopened, ready_for_review ]
+
+jobs:
+  allchecks:
+    runs-on: ubuntu-latest
+    permissions:
+      checks: read
+      contents: read
+    steps:
+      - uses: wechuli/allcheckspassed@v1
+        with:
+          # This seems to be working lately even for external
+          # contributors, so maybe we don't need to exclude it?
+          checks_exclude: "SonarCloud Code Analysis"
+          # Retry every minute for 30 minutes...
+          retries: 30

README.md

@@ -1,6 +1,6 @@
 # Chef Zero
 
-[![Build status](https://badge.buildkite.com/943881fa8cbc4bede24eebf34685a49fecd39ea88a316f60b1.svg?branch=master)](https://buildkite.com/chef-oss/chef-chef-zero-master-verify)
+[![Build status](https://github.com/chef/chef-zero/actions/workflows/allchecks.yml/badge.svg)](https://github.com/chef/chef-zero/actions/workflows/allchecks.yml)
 [![Gem Version](https://badge.fury.io/rb/chef-zero.svg)](http://badge.fury.io/rb/chef-zero)
 
 ## Description