Ansible Automation Hub Sigstore Integration

The Ansible Automation Hub Sigstore Integration project has three main objectives:
1. Implement a new type of managed credentials and verification logic for verifying Sigstore signatures on Ansible projects during project syncs on the automation controller.
2. Sign and verify Ansible collections and execution environments in Ansible Automation Hub.
3. Integrate Sigstore to existing tooling to enable Ansible content developers to sign and verify with Sigstore.