[WebRTC] Update sources after boringssl update in 265072@main

https://bugs.webkit.org/show_bug.cgi?id=257954

Reviewed by Youenn Fablet.

After borringssl update to M115, the list of sources in 'libwebrtc/CMakeLists.txt'
still had references to old files, which are now removed. New files have been added as well.

* Source/ThirdParty/libwebrtc/CMakeLists.txt:

Canonical link: https://commits.webkit.org/265185@main

Author: dpino