Update unified to 1.8.1

Author: James-Yu

package-lock.json

@@ -2678,9 +2678,9 @@
     "@typescript-eslint/eslint-plugin": "^8.6.0",
     "@typescript-eslint/parser": "^8.6.0",
     "@unified-latex/unified-latex-types": "1.8.0",
-    "@unified-latex/unified-latex-util-arguments": "1.8.0",
-    "@unified-latex/unified-latex-util-parse": "1.8.0",
-    "@unified-latex/unified-latex-util-to-string": "1.8.0",
+    "@unified-latex/unified-latex-util-arguments": "1.8.1",
+    "@unified-latex/unified-latex-util-parse": "1.8.1",
+    "@unified-latex/unified-latex-util-to-string": "1.8.1",
     "@vscode/test-electron": "^2.4.1",
     "@vscode/vsce": "^3.1.0",
     "c8": "^10.1.2",