Add missing vox unequipped sprite for explorer mask (#41405)

Mask on face

Resources/Textures/Clothing/Mask/gasexplorer.rsi/meta.json

@@ -1,7 +1,7 @@
 {
   "version": 1,
   "license": "CC-BY-SA-3.0",
-  "copyright": "Taken from tgstation at commit https://github.com/tgstation/tgstation/commit/4f6190e2895e09116663ef282d3ce1d8b35c032e. Reptilian edit by Nairod(Github). Vox state by Flareguy for SS14 | vulpkanin version edited by Floofers. Feroxi sprites made by @Stxcking",
+  "copyright": "Taken from tgstation at commit https://github.com/tgstation/tgstation/commit/4f6190e2895e09116663ef282d3ce1d8b35c032e. Reptilian edit by Nairod(Github). Vox state by Flareguy for SS14 | vulpkanin version edited by Floofers. Feroxi sprites made by @Stxcking | Vox unequipped by MissKay1994(Github)",
   "size": {
     "x": 32,
     "y": 32
@@ -39,6 +39,10 @@
     {
       "name": "equipped-MASK-reptilian",
       "directions": 4
+    },
+    {
+      "name": "up-equipped-MASK-vox",
+      "directions": 4
     }
   ]
 }