Add flags to enable/disable secrets in scaffold copy-secrets-job

[vipulagarwal]

Description

A change was introduced in #712 that makes TSA mandatory in scaffold copy-secret-job. A lot of users do not use TSA, especially when testing sigstore using scaffold as described in the blog post.

A flag to enable/disable the secrets used in scaffold copy-secret-job will help here. It is similar to the flags implemented in the tuf helm chart.