distsqlrun: remove redundant Close()

Close() is already called when timedOut is set.

fixes cockroachdb#13989

pkg/sql/distsqlrun/flow_registry.go

@@ -270,10 +270,6 @@ func (fr *flowRegistry) finishInboundStreamLocked(is *inboundStreamInfo) {
 		panic("double finish")
 	}
 
-	if is.timedOut {
-		is.receiver.Close(errors.Errorf("inbound stream timed out"))
-	}
-
 	is.finished = true
 	is.waitGroup.Done()
 }