Bump docker/build-push-action from 5 to 6 (#1181)

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](docker/build-push-action@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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Dhanshree Arora <DhanshreeA@users.noreply.github.com>

.github/workflows/ersilia-base-image-to-dockerhub.yml

@@ -65,7 +65,7 @@ jobs:
  type=sha
  
  - name: Build and push
- uses: docker/build-push-action@v5
+ uses: docker/build-push-action@v6
  with:
  context: .
  platforms: linux/amd64,linux/arm64

.github/workflows/ersilia-installer-to-dockerhub.yml

@@ -63,7 +63,7 @@ jobs:
  type=sha
  
  - name: Build and push
- uses: docker/build-push-action@v5
+ uses: docker/build-push-action@v6
  with:
  context: .
  platforms: linux/amd64,linux/arm64