Fixed:
- Fix race condition that could lead to use-after-free if the `Receiver` was polled asynchronously,
  but then dropped before completion. https://github.com/faern/oneshot/pull/74. RUSTSEC-2026-0005
- Fix race conditions/UB around atomic memory orderings. These were found by running tests under
  miri. https://github.com/faern/oneshot/pull/72