Bump the github-actions group across 1 directory with 3 updates

Bumps the github-actions group with 3 updates in the / directory: [sigstore/cosign-installer](https://github.com/sigstore/cosign-installer), [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) and [docker/build-push-action](https://github.com/docker/build-push-action).


Updates `sigstore/cosign-installer` from 4.1.0 to 4.1.1
- [Release notes](https://github.com/sigstore/cosign-installer/releases)
- [Commits](https://github.com/sigstore/cosign-installer/compare/v4.1.0...v4.1.1)

Updates `docker/setup-buildx-action` from 3.12.0 to 4.0.0
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](https://github.com/docker/setup-buildx-action/compare/v3.12.0...v4)

Updates `docker/build-push-action` from 6.19.2 to 7.0.0
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v6.19.2...v7

)

---
updated-dependencies:
- dependency-name: sigstore/cosign-installer
  dependency-version: 4.1.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: github-actions
- dependency-name: docker/setup-buildx-action
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
- dependency-name: docker/build-push-action
  dependency-version: 7.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: github-actions
...

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