Fix research_sync echoing synced research back to the controller (#1111)

The on_research_finished handler read ignore_research_finished from the
research_sync global, which is the table of RCON functions and never has that
field. The flag that sync_technologies and research_technology set lives on the
script data, so the check never returned and research that came from the
controller was sent back as newly finished. The handler now reads the flag from
the script data.

Co-authored-by: ILLISIS <jayson.harris01@gmail.com>
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

plugins/research_sync/module/sync.lua

@@ -114,7 +114,7 @@ end
 --- @param event EventData.on_research_finished
 sync.events[defines.events.on_research_finished] = function(event)
 	local script_data = get_script_data()
-	if research_sync.ignore_research_finished then
+	if script_data.ignore_research_finished then
 		return
 	end