Update to latest syntax file (#655)

Author: github-actions[bot]

editors/code/syntaxes/Luau.tmLanguage.json

@@ -60,6 +60,9 @@
     },
     {
       "include": "#type_annotation"
+    },
+    {
+      "include": "#attribute"
     }
   ],
   "repository": {
@@ -150,6 +153,9 @@
         {
           "include": "#comment"
         },
+        {
+          "include": "#attribute"
+        },
         {
           "begin": "(:)",
           "beginCaptures": {
@@ -749,6 +755,22 @@
           ]
         }
       ]
+    },
+    "attribute": {
+      "patterns": [
+        {
+          "name": "meta.attribute.luau",
+          "match": "(@)([a-zA-Z_][a-zA-Z0-9_]*)",
+          "captures": {
+            "1": {
+              "name": "keyword.operator.attribute.luau"
+            },
+            "2": {
+              "name": "storage.type.attribute.luau"
+            }
+          }
+        }
+      ]
     }
   }
 }