improve deprecated syntax

.github/workflows/docker-publish.yml

@@ -19,21 +19,25 @@ jobs:
         uses: actions/checkout@v3
 
       - name: prepare tag 
+        id: prepare_tag
         run: |
-            export IMAGE_ID=jambonz/$IMAGE_NAME
+            IMAGE_ID=jambonz/$IMAGE_NAME
 
             # Strip git ref prefix from version
-            export VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
+            VERSION=$(echo "${{ github.ref }}" | sed -e 's,.*/\(.*\),\1,')
 
             # Strip "v" prefix from tag name
             [[ "${{ github.ref }}" == "refs/tags/"* ]] && VERSION=$(echo $VERSION | sed -e 's/^v//')
 
             # Use Docker `latest` tag convention
-            [ "$VERSION" == "main" ] && export VERSION=latest
+            [ "$VERSION" == "main" ] && VERSION=latest
 
             echo IMAGE_ID=$IMAGE_ID
             echo VERSION=$VERSION
 
+            echo "{image_id}={$IMAGE_ID}" >> $GITHUB_OUTPUT
+            echo "{version}={$VERSION}" >> $GITHUB_OUTPUT
+
       - name: Login to Docker Hub 
         uses: docker/login-action@v2
         with:
@@ -45,7 +49,7 @@ jobs:
         with:
           context: .
           push: true
-          tags: ${{ env.IMAGE_ID }}:${{ env.VERSION }}
+          tags: ${{ steps.prepare_tag.outputs.image_id }}:${{ steps.prepare_tag.outputs.version }}
           build-args: |
             GITHUB_REPOSITORY=$GITHUB_REPOSITORY
             GITHUB_REF=$GITHUB_REF