test(node): add missing owner_did field to fails-closed seed update (#229)

PRs #113 and #145 raced: #145 added owner_did to ReceivedRefUpdate and
updated its own call sites, but the seed initializer in
list_repo_events_fails_closed_when_repo_lookup_errors (added by #113)
was never updated, so main fails to compile test targets (E0063).
This breaks clippy --all-targets, both test jobs, and MSRV on CI,
including the release PR #182.

owner_did stays None here on purpose: the test exercises the legacy
None-branch slug fallback.

Co-authored-by: Kevin Codex <kevin@gitlawb.com>

Author: kevincodex1

crates/gitlawb-node/src/test_support.rs

@@ -1577,6 +1577,7 @@ mod tests {
                 cert_id: None,
                 received_at: Utc::now().to_rfc3339(),
                 from_peer: "peer".to_string(),
+                owner_did: None,
             })
             .await
             .expect("seed private gossip update");