Update jboss/keycloak Docker tag to v13

Summary

Requesting application be updated to a newer version. Version 13 has just now released
https://www.keycloak.org/2021/05/keycloak-1300-released.html

Version Information

Current version: 12.0.4

Updated version: 13.0.0

Under support: new major version

Definition of Done

Hardening:

• Container builds successfully
• Container version has been updated in greylist file
• Branch has been merged into development

Justifications:

• All findings have been justified per the above documentation
• Justifications have been provided to the container hardening team

Approval Process:

• Peer review from Container Hardening Team
• Findings Approver has reviewed and approved all justifications
• Approval request has been sent to Authorizing Official
• Approval request has been processed by Authorizing Official

/cc @ironbank-notifications/updates