Flaky `DispatcherSpec` on JS

[djspiewak]

[info] ==> X cats.effect.std.DispatcherSuite.sequential dispatcher (cancelable = false) - await = true - report exception if raised during unsafeRunAndForget 3.071s munit.ComparisonFailException: tests/shared/src/test/scala/cats/effect/std/DispatcherSuite.scala:452
[info] 451:          IO.fromFutureCancelable(IO((t.future, IO.unit))).timeoutTo(3.second, IO.pure(false)))
[info] 452:        .flatMap(t => IO(assertEquals(t, true)))
[info] 453:    }
[info] values are not the same
[info] => Obtained
[info] false
[info] => Diff (- expected, + obtained)
[info] -true

https://github.com/typelevel/cats-effect/actions/runs/20564823931/job/59061291706