fixes tech disk uploading taking 5 seconds of total cpu (#90005)

## About The Pull Request
idk if the master crash thing was effectively solved in the last week
but now it is, uploading the debug tech disk has gone from 5 seconds of
total cpu to 0.58 seconds. also since it filters out already added
designs and nodes more it costs much less to upload it redundantly than
before.

before (uploading disk to web and web to disk)

[message(5).txt](https://github.com/user-attachments/files/19205791/message.5.txt)


uploading 1 time

[message(3).txt](https://github.com/user-attachments/files/19205746/message.3.txt)
uploading 7 times

[message(4).txt](https://github.com/user-attachments/files/19205756/message.4.txt)
## Why It's Good For The Game
why did it take 5 seconds to go over 1000 things? because it was
redundantly doing things 10,000s of times
## Changelog
🆑
refactor: tech disk uploading isnt super slow anymore (much harder to
crash spacetime with it)
/🆑

---------

Co-authored-by: LemonInTheDark <58055496+LemonInTheDark@users.noreply.github.com>

code/modules/research/techweb/_techweb.dm

@@ -149,10 +149,10 @@
 		CHECK_TICK
 		if(get_available_nodes()[i] || get_researched_nodes()[i] || get_visible_nodes()[i])
 			receiver.hidden_nodes -= i //We can see it so let them see it too.
-	for(var/i in researched_nodes)
+	for(var/i in researched_nodes - receiver.researched_nodes)
 		CHECK_TICK
 		receiver.research_node_id(i, TRUE, FALSE, FALSE)
-	for(var/i in researched_designs)
+	for(var/i in researched_designs - receiver.researched_designs)
 		CHECK_TICK
 		receiver.add_design_by_id(i)
 	receiver.recalculate_nodes()
@@ -486,7 +486,7 @@
 		return
 	if(researched)
 		researched_nodes[node.id] = TRUE
-		for(var/id in node.design_ids)
+		for(var/id in node.design_ids - researched_designs)
 			add_design(SSresearch.techweb_design_by_id(id))
 	else
 		if(available)