chore(ci): update GitHub Actions workflow

- Upgrade actions/checkout to v4
- Upgrade pnpm/action-setup to v4
- Add Docker build job using buildx and GHCR
- Use docker/login-action and build-push-action for publishing
- Ignore changes to Markdown and docs in CI triggers

Author: iodsky

.github/workflows/ci.yml

@@ -3,8 +3,14 @@ name: BrainBytes CI
 on:
   push:
     branches: [main, develop]
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
   pull_request:
     branches: [main, develop]
+    paths-ignore:
+      - "**.md"
+      - "docs/**"
   workflow_dispatch:
 
 jobs:
@@ -14,21 +20,15 @@ jobs:
 
     steps:
       - name: Check out repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install pnpm and Node.js
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: "10.10.0"
           node-version: "24.1.0"
           cache: "pnpm"
 
-      # - name: Setup Node.js
-      #   uses: actions/setup-node@v2
-      #   with:
-      #     node-version: "24.1.0"
-      #     cache: "pnpm"
-
       - name: Install dependencies
         working-directory: ./src
         run: pnpm install --no-frozen-lockfile
@@ -48,25 +48,48 @@ jobs:
 
     steps:
       - name: Check out repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Install pnpm and Node.js
-        uses: pnpm/action-setup@v2
+        uses: pnpm/action-setup@v4
         with:
           version: "10.10.0"
           node-version: "24.1.0"
           cache: "pnpm"
 
-      # - name: Setup Node.js
-      #   uses: actions/setup-node@v2
-      #   with:
-      #     node-version: "24.1.0"
-      #     cache: "pnpm"
-
       - name: Install dependencies
         working-directory: ./src
         run: pnpm install --no-frozen-lockfile
 
       - name: Run backend tests
         working-directory: ./src
         run: pnpm test
+
+  build:
+    name: Build Docker Image
+    needs: ["lint", "test"]
+    runs-on: ubuntu-latest
+    environment: GitHub actions
+
+    steps:
+      - name: Check out repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GHCR
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push Image
+        uses: docker/build-push-action@v4
+        with:
+          context: ./src
+          push: true
+          tags: ghcr.io/${{ github.repository_owner }}-api:latest
+          cache-from: type=gha
+          cache-to: type=gha,mode=max