Renovate: Update jboss/keycloak Docker tag to v13

Renovate has identified updated artifacts for this project.

ironbank-bot does not currently support updating the greylist file to match the version indicated by Renovate. Not does it support validating pipeline status. Please ensure these are handled manually.

Definition of Done:

• Merge topic branch into development
• Merge development into master
• If there are new findings, attach justifications
• Assign label Approval