chore(deps): update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/main.yaml

@@ -105,7 +105,7 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
       - name: Build and push docker image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           push: false
           tags: nestjs:latest

.github/workflows/pull_request.yaml

@@ -110,7 +110,7 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
       - name: Build and push docker image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           push: false
           tags: nestjs:latest