chore: remove ignored files from tracking

frontend/node_modules/css-tree/cjs/utils/create-custom-error.cjs

@@ -1,18 +0,0 @@
-'use strict';
-
-function createCustomError(name, message) {
-    // use Object.create(), because some VMs prevent setting line/column otherwise
-    // (iOS Safari 10 even throws an exception)
-    const error = Object.create(SyntaxError.prototype);
-    const errorStack = new Error();
-
-    return Object.assign(error, {
-        name,
-        message,
-        get stack() {
-            return (errorStack.stack || '').replace(/^(.+\n){1,3}/, `${name}: ${message}\n`);
-        }
-    });
-}
-
-exports.createCustomError = createCustomError;