Add metal icon (#21720)

Release Notes:

- Added file icon for metal

---------

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

assets/icons/file_icons/file_types.json

@@ -113,6 +113,7 @@
     "mdf": "storage",
     "mdx": "document",
     "metadata": "code",
+    "metal": "metal",
     "mjs": "javascript",
     "mka": "audio",
     "mkv": "video",
@@ -322,6 +323,9 @@
     "lua": {
       "icon": "icons/file_icons/lua.svg"
     },
+    "metal": {
+      "icon": "icons/file_icons/metal.svg"
+    },
     "nim": {
       "icon": "icons/file_icons/nim.svg"
     },

assets/icons/file_icons/metal.svg

@@ -0,0 +1 @@
+<svg width="16" height="16" fill="none" xmlns="http://www.w3.org/2000/svg"><path fill-rule="evenodd" clip-rule="evenodd" d="M4.56 4.502 3.25 3.027V11.5h1.5V6.973l2.69 3.025 1.31 1.475V7.918l3.306 3.582h2.042L8.55 5.491 7.25 4.081V7.528L4.56 4.502Z" fill="#000"/></svg>