Add workflow to check gql has been executed

.gitea/workflows/tests.yaml

@@ -0,0 +1,17 @@
+name: Tests
+on:
+  pull_request:
+
+env:
+  NIXPKGS_ALLOW_UNFREE: 1
+
+jobs:
+  install:
+    name: Tests
+    runs-on: nixos-x86_64-linux
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          submodules: recursive
+      - name: graphql-codegen causes no changes
+        run: ./bin/assert-no-changes-wrapper.sh