build: Setup schema validation action

.github/workflows/check-schema.yml

@@ -0,0 +1,19 @@
+name: Check Schema
+on:
+  push:
+    branches: "**"
+    tags-ignore: ["**"]
+    pull_request:
+
+jobs:
+  test:
+    name: Annotate Breaking Changes
+    runs-on: ubuntu-latest
+    if: "${{ github.event_name != 'pull_request' || github.repository != github.event.pull_request.head.repo.full_name }}"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@master
+      - uses: kamilkisiela/graphql-inspector@master
+        with:
+          schema: 'main:schema.graphql'
+          approve-label: breaking