add service, update host table

Author: wing328

.github/workflows/samples-scala-client.yaml

@@ -38,8 +38,19 @@ jobs:
           - samples/client/petstore/scala-sttp
           - samples/client/petstore/scala-sttp-circe
           - samples/client/petstore/scala-sttp4
+    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: Add hosts to /etc/hosts
+        run: |
+            sudo echo "127.0.0.1 petstore.swagger.io" | sudo tee -a /etc/hosts
       - uses: actions/setup-java@v5
         with:
           distribution: 'temurin'