RC v12.0 released — re-verify robocol (pinned v11.2)

[github-actions]

Upstream FtcRobotController is at v12.0; robocol is validated
against v11.2.

Re-verify the wire formats against the tracked source files, capture a
fresh session if anything changed, then bump
robocol::tracked_rc::RELEASE_TAG.

Tracked source files to diff v11.2..v12.0:
RobocolConfig.java, Command.java, RobotCoreCommandList.java,
PeerDiscovery.java, Heartbeat.java, KeepAlive.java, Gamepad.java, and
the packet/datagram framing classes.