chore: bump docker/build-push-action from 5 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v5...v6)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/docker-publish.yml

@@ -46,7 +46,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
       -
         name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: '.'
           file: './Dockerfile'
@@ -88,7 +88,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
       -
         name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: '.'
           file: './Dockerfile'
@@ -143,7 +143,7 @@ jobs:
           password: ${{ secrets.GITHUB_TOKEN }}
       -
         name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: '.'
           file: './Dockerfile'

.github/workflows/docker-test.yml

@@ -27,7 +27,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
       -
         name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: '.'
           file: './Dockerfile'
@@ -35,7 +35,7 @@ jobs:
           tags: ttionya/vaultwarden-backup:dev
       -
         name: Build test Docker image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: '.'
           file: './tests/Dockerfile'