WIP: Attempt at building and caching the Docker image

.github/workflows/continuous-integration.yml

@@ -8,6 +8,27 @@ on:
       - develop
 
 jobs:
+  name: Build and cache image
+  runs-on: ubuntu-latest
+  steps:
+    -
+    name: Checkout
+    uses: actions/checkout@v4
+      -
+    name: Set up Docker Buildx
+    uses: docker/setup-buildx-action@v3
+      -
+    name: Build and cache image
+    uses: docker/build-push-action@v6
+    with:
+      context: .
+      file: ./Dockerfile
+      build-args: RAILS_ENV=test
+      push: false
+      tags: app_test:latest
+      cache-from: type=gha
+      cache-to: type=gha,mode=min
+
   test:
     runs-on: ubuntu-latest