Partially moves the iconoclast's repeater behind a knowledge book (#95580)

## About The Pull Request

I considered at first moving the siege weapon variant (the thing you use
to craft the repeater) behind the crafting book too, but the siege
weapon version isn't strong or problematic enough to need it, and that
would be basically a soft-removal since nobody would make it except to
make the iconoclast's repeater.

The iconoclast's repeater (specifically making the handheld version) now
requires use of a crafting book to learn how to make, which spawns in
maints in the same loot pool as the other "good" improvised weapons.
Without it, the welded-on version of the repeater may still be produced.

## Why It's Good For The Game

While they are fairly strong and the infinite ammo thing removes the
requirement to have weapon rechargers (trivializing antagonists like
blobs and xenomorphs) the main issue though is their mass availability.
Specifically, you can build autocrafters to make as many as them as you
want because of how trivially easy they are to produced. The current
"rule" with improvised weapons is if they are on par with cargo
ordered/armory stocked weapons, they have to be learned from a
maintenance book. This limits how freely they can be made and
distributed without nerfing them into the ground in order to make them
an occasional occurrence like the heroic laser musket, which I think is
probably the best way to handle it.

code/datums/components/crafting/ranged_weapon.dm

@@ -353,7 +353,7 @@
 	)
 	time = 10 SECONDS
 	category = CAT_WEAPON_RANGED
-	crafting_flags = CRAFT_CHECK_DENSITY
+	crafting_flags = CRAFT_CHECK_DENSITY | CRAFT_MUST_BE_LEARNED
 
 
 /datum/crafting_recipe/large_ballista