[AI-687] openapi migrate ci from drone to gh actions

.github/workflows/ci.yml

@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch:
+
+concurrency:
+  group: ci-${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  IMAGE_TAG: openapi-ci:local
+  DOCKER_BUILDKIT: "1"
+
+jobs:
+  openapi:
+    name: OpenAPI (Docker)
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: docker/setup-buildx-action@v3
+
+      - uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: Dockerfile
+          target: builder
+          push: false
+          load: true
+          tags: ${{ env.IMAGE_TAG }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Validate
+        run: docker run --rm ${{ env.IMAGE_TAG }} openapi-generator-cli validate -i api.yaml
+
+      - name: Generate
+        run: docker run --rm ${{ env.IMAGE_TAG }} openapi-generator-cli generate -i api.yaml -g openapi-yaml