Fix race condition (also a regression of the PR 19139)#19221

Open

ahrtr wants to merge 3 commits intoetcd-io:mainfrom ahrtr:race-20250117

+29-8

Commits on Jan 17, 2025

Enhance method (*serveCtx) serve to wait for all goroutines to complete before it returns
ahrtr
committed
Ensure all goroutines created by StartEtcd to complete before closing the errc
ahrtr
committed
Update TestAuthGracefulDisable to wait for member to get started
ahrtr
committed