await_any_or_fail deadlocks when only later futures complete

[EdmondDantes]

Repro

<?php
use Async\Future;
use Async\FutureState;
use function Async\spawn;
use function Async\await_all;

$s1 = new FutureState();
$s2 = new FutureState();
$f1 = new Future($s1);
$f2 = new Future($s2);

$P = spawn(fn() => $s2->complete(2));      // completes F2
$A = spawn(fn() => \Async\await_any_or_fail([$f1, $f2]));
await_all([$P, $A]);

Expected: A receives 2, both coroutines finish.

Actual: deadlock. Output:

=== DEADLOCK REPORT START ===
Coroutines waiting: 2, active_events: 0

Coroutine 6 spawned at :0, suspended at repro.php:19 (main)
  waiting for: Coroutine 10 ...
Coroutine 10 spawned at repro.php:15, suspended at repro.php:16
  waiting for:

If the producer completes the first future ($s1->complete(1)) instead, the test passes — the awaiter wakes up and returns 1. So await_any_or_fail appears to register a listener only on the first trigger of the iterable, ignoring the rest.

Where it was found

fuzzy_tests/await/await_any.feature, Examples row which=F2, deterministic
under FIFO and every random scheduler tested. Found by the chaos harness
introduced in #102.

[EdmondDantes]

Investigation: bug is Future-specific

Existing tests/await/*.phpt for await_any* exclusively pass arrays of
Coroutines as triggers — none of them combine await_any_or_fail with
Async\Future instances. That is why the bug has slipped through.

Verified the symmetric case with coroutines works:

$c1 = spawn(fn() => { suspend(); suspend(); suspend(); return "first"; });  // late
$c2 = spawn(fn() => "second");                                                // wins
$w  = spawn(fn() => echo \Async\await_any_or_fail([$c1, $c2]));
await_all([$c1, $c2, $w]);
// prints "second" — correct

So the trigger-registration path for Future in await_any_or_fail
appears not to be wired up symmetrically with the Coroutine path. The
listener for the second (and presumably any later) Future trigger is
either not installed or never fires.

Suggests adding a phpt that uses Future triggers for every
await_any* / await_first* variant.