Replace ArrayView with std::span in api/

ArrayView is an alias to std::span. This change switch to use
std::span directly instead of through the alias.

Search&Replace MakeArrayView and ArrayView with std::span
Search&Replace include "api/array_view.h" with include <span>
Remove <span> include where std::span is not mentioned in the file
Remove build dependencies on array_view target

Updated comment in audio_frame.cc to be more accurate matching one of
the behavior changes between ArrayView and std::span

Bug: webrtc:439801349
Change-Id: Iec42e1bf3ff5539211e8a4c85773ba08cf1412dd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/461060
Commit-Queue: Evan Shrubsole <eshr@webrtc.org>
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Evan Shrubsole <eshr@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47315}