chore: remove ignored files from tracking

frontend/node_modules/css-tree/lib/syntax/node/String.js

@@ -1,19 +0,0 @@
-import { String as StringToken } from '../../tokenizer/index.js';
-import { decode, encode } from '../../utils/string.js';
-
-export const name = 'String';
-export const structure = {
-    value: String
-};
-
-export function parse() {
-    return {
-        type: 'String',
-        loc: this.getLocation(this.tokenStart, this.tokenEnd),
-        value: decode(this.consume(StringToken))
-    };
-}
-
-export function generate(node) {
-    this.token(StringToken, encode(node.value));
-}