Start using cosign transparency log using rekor and fulcio

[marcofranssen]

By using cosigns experimental feature it will start using fulcio and rekor.

This adds additional security by adding a transparancy log as well PKCS11 based certificates.

As the feature is still experimental we might want to hold back for a bit to have this feature mature a bit more.

We need to add the certificate lines back

abc16c4

as well enable the experimental feature see https://github.com/caarlos0/goreleaserfiles/blob/main/cosign_docker.yml#L6

Doing so enables us to do keyless code signing of our releases.