ci: add github action

.github/workflows/verify.yaml

@@ -0,0 +1,58 @@
+name: verify
+
+on:
+  push:
+    branches:
+      - 'main'
+    tags:
+      - 'v*'
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    name: Build & Test
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ~1.22
+          cache: true
+
+      - name: go version
+        run: |
+          go version
+
+      - name: build
+        run: |
+          make
+
+      - name: verify that generated code is up-to-date
+        run: |
+          # make (which we ran in the previous step) will implicitly also run the targets manifests & generate, which
+          # could potentially modify code that is under version control, if changes have been comitted that would have
+          # required updating manifests or generated code and these updates have not been done.
+          git diff --exit-code
+
+      - name: lint
+        run: |
+          make lint
+
+      - name: test
+        run: |
+          make test
+
+      - name: build container image
+        run: |
+          # Instead of running make docker-build, we run docker build directly.
+          docker build -t dash0-operator-controller:latest .
+
+      # TODO look into https://github.com/helm/kind-action and run e2e test in GH action
+      # - name: end-to-end test
+      #   run: |
+      #     make test-e2e