chore: Update Docker actions in conformance workflow

Updated Docker Bake action version and added Buildx setup step.

Signed-off-by: Erez Rokah <[email protected]>

Author: erezrokah

.github/workflows/conformance.yml

@@ -20,11 +20,13 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       -
         name: Build image
-        uses: docker/bake-action@v4
-        with:
-          targets: image-local
+        uses: docker/bake-action@v6
       -
         name: Start distribution server
         run: |