chore(relay)!: make v1 hop opt-in

[richard-ramos]

Summary

This PR changes the default relay service codec set so Relay.new() advertises only circuit relay v2 HOP.

Legacy relay v1 HOP remains available, but only when explicitly constructing the relay with circuitRelayV1 = true.

This is needed because relay v1 HOP currently bridges raw streams and does not apply the relay v2 data/duration limits. Previously, enabling the default relay service exposed that legacy path implicitly, even when users intended to run the bounded v2 relay.

Affected Areas

• Protocol Logic
  Circuit relay service protocol advertisement.

Impact on Library Users

This is a breaking behavior change for users relying on default Relay.new() to serve relay v1 HOP. Those users must opt in with Relay.new(circuitRelayV1 = true).

Users relying on the default v2 relay behavior continue to get v2 HOP.

Risk Assessment

The main compatibility risk is for peers or deployments that still expect a default relay service to support v1 HOP. The change reduces accidental exposure of legacy v1 circuits when users intended to run the default v2 relay service.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.29%. Comparing base (af9651a) to head (969e74e).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2785      +/-   ##
==========================================
- Coverage   81.30%   81.29%   -0.02%     
==========================================
  Files         171      171              
  Lines       31013    31013              
  Branches       12       12              
==========================================
- Hits        25216    25212       -4     
- Misses       5797     5801       +4     

Files with missing lines	Coverage Δ
libp2p/protocols/connectivity/relay/relay.nim	91.22% <100.00%> (ø)

... and 3 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.