feat: split sbp admin

[amandazhuyilan]

Description

AAI-856: Split SBP admin into platform and bundle

Changes

• removed PLATFORM_BUNDLE_GROUP_MAP and the branch that double-linked the SBP platform role to the bundle group. Now link_admin_roles links each role to exactly one resource.
  • The new bundle role auto-links to biocommons/group/sbp_workflow_execution via the existing group-admin naming regex

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have added unit / integration tests that prove my fix is effective or that my feature works
• I have run all tests locally and they pass
• I have updated the documentation (if applicable)
• For any new secrets, I have updated the shared spreadsheet and the GitHub Secrets.

How to Test Manually (if necessary)

uv run pytest