feat(balance): allow the PA leg mount to holster small launchers (#8235)

enable power armor leg mount holstering of small grenade launchers

several grenade launchers were too small to be holstered in the power armor weapons rack, this enables them to be stored in the leg mount hardpoint

Author: ZChris13

data/json/items/armor/power_armor.json

@@ -468,7 +468,7 @@
       "max_volume": "3 L",
       "min_volume": "250 ml",
       "flags": [ "SHEATH_KNIFE", "SHEATH_SWORD", "BELT_CLIP" ],
-      "skills": [ "pistol", "smg", "shotgun", "rifle" ]
+      "skills": [ "pistol", "smg", "shotgun", "rifle", "launcher" ]
     },
     "flags": [ "POWERARMOR_MOD", "COMPACT", "STURDY", "WAIST" ]
   },