Update boilerplate files in older work item repo templates

[dif-admin]

After TSC review of this catch-all work item template (https://github.com/decentralized-identity/template-for-work-items), ensure older, specialized work item repo templates are up-to-date. That includes:

• https://github.com/decentralized-identity/template-for-registry-workitems
• https://github.com/decentralized-identity/template-for-profile-workitems
• https://github.com/decentralized-identity/template-IETF-bound