- Upgrade the version of GStreamer for Windows
This upgrades the Windows build to use the most recent version of
GStreamer. This is necessary to upgrade our GStreamer dependency.
- Stop shipping GStreamer binaries on Linux
The binary bundle of GStreamer that we package is not used to compile --
only to run layout tests. It's too old for the APIs that we are using
(as evidenced by needed 1.18 for WebRTC) and nowadays Linux
distributions carry a new version so it's unecessary for our build
machines. No longer using this binary bundle will allow us to upgrade
our GStreamer dependency -- which now has stricter checks that we
are using at least version 1.18.
- Upgrade media to use newer versions of GStreamer / GLib dependencies
