Spin up the PostgreSQL service in CI

.github/workflows/ci.yml

@@ -11,6 +11,17 @@ jobs:
   test:
     name: "Test"
     runs-on: ubuntu-latest
+    services:
+      db:
+        image: postgres:latest
+        ports: ["5432:5432"]
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: postgres
+        options: >-
+          --health-cmd pg_isready --health-interval 10s --health-timeout 5s
+          --health-retries 5
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1