Rollup merge of #152648 - JonathanBrouwer:debug_spurious, r=jhpratt

Remove timing assertion from `oneshot::send_before_recv_timeout`

This test regularly spuriously fails in CI, such as rust-lang/rust#152632 (comment)
We can just remove the assertion but I'd like to understand why, so I'm adding more information to the assert

Author: jhpratt