ignore any leading/trailing whitespace in the peerlist

[Geometer1729]

Cherry-pick #15739 into compatible

Checklist:

• [x] Dependency versions are unchanged
  • Notify Velocity team if dependencies must change in CI
• [ ] Modified the current draft of release notes with details on what is completed or incomplete within this project
• [ ] Document code purpose, how to use it
  • Mention expected invariants, implicit constraints
• [ ] Tests were added for the new behavior
  • Document test purpose, significance of failures
  • Test names should reflect their purpose
• [ ] All tests pass (CI will check this if you didn't)
• [ ] Serialized types are in stable-versioned modules
• [ ] Does this close issues? List them already closed

[Geometer1729]

!ci-build-me

[Geometer1729]

!ci-build-me