Update docker/metadata-action action to v6

Author: xdev-renovate

.github/workflows/release.yml

@@ -248,7 +248,7 @@ jobs:
 
     - name: Extract metadata (tags, labels) for Docker
       id: meta
-      uses: docker/metadata-action@v5
+      uses: docker/metadata-action@v6
       with:
         images: |
           ${{ secrets.DOCKERHUB_USERNAME }}/mockserver

.github/workflows/test-deploy.yml

@@ -98,7 +98,7 @@ jobs:
 
     - name: Extract metadata (tags, labels) for Docker
       id: meta
-      uses: docker/metadata-action@v5
+      uses: docker/metadata-action@v6
       with:
         images: |
           ${{ secrets.DOCKERHUB_USERNAME }}/mockserver