在 go test -count>1 期间,TestRaft_HasExistingState 会间歇失败

`TestRaft_HasExistingState` intermittently fails when the package is run with `-count>1`. I could not reproduce it at `-count=1` in 47 attempts across three scopes, so it looks specific to in-process repetition rather than something you would hit in normal CI. Raising it because `-count=N` with `-shuffle` is the usual way to hunt genuine flakes, and this adds noise to that on the raft package. As far as I can tell it is not in #372's list and has no existing issue, PR or commit.