build: build docker images sequentially

Author: markwoon

.github/workflows/release-docker.yml

@@ -11,7 +11,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Set appVersion
         uses: bhowell2/github-substring-action@v1
@@ -23,7 +23,7 @@ jobs:
       - run: echo "Version = ${{steps.appVersion.outputs.substring}}"
 
       - name: Set up JDK
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@v5
         with:
           distribution: temurin
           java-version: 17
@@ -49,12 +49,17 @@ jobs:
 
       - name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           platforms: linux/amd64,linux/arm64
           push: true
           tags: pgkb/pharmcat:latest,pgkb/pharmcat:${{steps.appVersion.outputs.substring}}
+        env:
+          # Explicitly enable BuildKit (optional with Buildx)
+          DOCKER_BUILDKIT: 1
+          # Limit to one parallel build for lower RAM
+          BUILDKIT_MAX_PARALLELISM: 1
 
 
       - name: Send Slack notification on failure