Update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/build-image.yml

@@ -96,7 +96,7 @@ jobs:
           echo "::set-output name=image_ref::${DOCKER_TAG})"
 
       - name: Build Docker Image
-        uses: docker/build-push-action@v2.6.1
+        uses: docker/build-push-action@v6.18.0
         with:
           tags: |
             ${{ env.IMAGE_NAME }}:${{ env.DOCKER_TAG }}

.github/workflows/build-pixi-image.yml

@@ -92,7 +92,7 @@ jobs:
           echo "::set-output name=image_ref::${DOCKER_TAG})"
 
       - name: Build Docker Image
-        uses: docker/build-push-action@v2.6.1
+        uses: docker/build-push-action@v6.18.0
         with:
           tags: |
             ${{ env.IMAGE_NAME }}:${{ env.DOCKER_TAG }}