muster release v5.34.3

muster test dumps its goroutines while a call is blocked past its deadline. A stalled call’s diagnostics (#1260) were taken after the call had unwound, so the blocked frame was gone. In CI a poll with a 20s budget came back only after 90s, and muster serve never logged its request. The call ignored its context somewhere in the harness’s client path. A call to muster serve that is still running 2s after its context’s deadline now has the harness’s goroutines recorded while it is blocked, as harness_goroutines_at_overrun in the report, and the failure line points at it. (#1206)