Replace ArrayView with std::span in modules/audio_processing/aec3

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

No-Iwyu: suggested missing includes are questionable, and such question is out of scope of this change.
Bug: webrtc:439801349
Change-Id: Iaa233c972c1420563862f43530ed354cddbcaf8c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/455800
Commit-Queue: Sam Zackrisson <saza@webrtc.org>
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47117}