[roll] Roll fuchsia [starnix] input_file event buffer is lock free

Starnix virtual input files stored their buffer as a Mutex<VecDeque>.
This has the potential lead to contention causing input pipeline delays.

Swap this out for a lock free data structure. I've opted for
crossbeam::queue::SegQueue, which is the same type used by
//src/lib/mpmc.

Incidentally, this change removes an INFO log that reported how many
events are left in the buffer if it was not empty. Keeping the log the
same would add atomic memory accesses, which is probably small overhead
but since I'm not sure how important this log is I opted to take it
out.

Original-Original-Fixed: 513648643

Original-Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1612992
Original-Original-Revision: b0c97b0357e3fac6225c6536dfef80bc22efced8
GitOrigin-RevId: 1c3812142f4fb4b7cce023264f59270f3bac8b8f
Change-Id: I5fe7af4d2e6711316a49d0596a0e8fbed012152f
Reviewed-on: https://fuchsia-review.googlesource.com/c/integration/+/1618790
Cr-Commit-Position: refs/heads/main@{#193045}