Fix rockets embedding in people (#76136)

## About The Pull Request
Rockets can't embed anymore and are now blunt objects (so they cause
blunt wounds instead)
This is what could happen before:

![rocket_embed](https://github.com/tgstation/tgstation/assets/113535457/b1213460-fb87-4c28-bde9-454a271a38fc)
## Why It's Good For The Game
I've been told that the embedding is not intentional, so this PR fixes
an oversight
## Changelog
🆑
fix: Rockets can no longer embed in people and cause blunt wounds
instead of piercing
/🆑

code/modules/projectiles/projectile/special/rocket.dm

@@ -16,6 +16,9 @@
 	desc = "Boom."
 	icon_state= "missile"
 	damage = 50
+	sharpness = NONE
+	embedding = null
+	shrapnel_type = null
 	ricochets_max = 0
 	/// Whether we do extra damage when hitting a mech or silicon
 	var/anti_armour_damage = 0