add workflow to test crystal client

Author: wing328

.github/workflows/samples-crystal.yaml

@@ -0,0 +1,34 @@
+name: Samples Crystal clients
+
+on:
+  push:
+    paths:
+      - samples/client/petstore/crystal/**
+  pull_request:
+    paths:
+      - samples/client/petstore/crystal/**
+jobs:
+  build:
+    name: Build Crystal projects
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sample:
+          # clients
+          - samples/client/petstore/crystal/
+    services:
+      petstore-api:
+        image: swaggerapi/petstore
+        ports:
+          - 80:8080
+        env:
+          SWAGGER_HOST: http://petstore.swagger.io
+          SWAGGER_BASE_PATH: /v2
+    steps:
+      - uses: actions/checkout@v5
+      - name: Install Crystal
+        uses: crystal-lang/install-crystal@v1
+      - name: Run tests
+        run: crystal spec
+        working-directory: ${{ matrix.sample }}