remove unused support for more than four spatial layer descriptions
of temporal layers
BUG=webrtc:12000
Change-Id: I087bcd020897898636bdf9c838abafa8c73c53f3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/281320
Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@microsoft.com>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38646}
05b58ad77e