chore: update defaults

[codyshoffner]

Description

• Update some defaults in the template that have gotten stale.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide Steps followed

[nywilken]

As a first past this looks good to get rid of things that are no longer needed or outdated. I left a nit and a question.

That said, I found the mixing of Must with Should and May to be a bit confusing since they are all under the Must Have section.

For a second pass, It would be great to cluster the requirements into capability-based groupings that need to be met. For Example:

• Networking & Service Exposure
• Identity & Access Management (SSO/Keyclock)
• Security & Hardening
• UDS Core Interoperability
• Testing …
• Configuration …