fix: Add nixpacks configuration for Astro deployment

dealplustech-astro/node_modules/csso/lib/restructure/prepare/createDeclarationIndexer.js

@@ -0,0 +1,31 @@
+import { generate } from 'css-tree';
+
+class Index {
+    constructor() {
+        this.map = new Map();
+    }
+    resolve(str) {
+        let index = this.map.get(str);
+
+        if (index === undefined) {
+            index = this.map.size + 1;
+            this.map.set(str, index);
+        }
+
+        return index;
+    }
+};
+
+export default function createDeclarationIndexer() {
+    const ids = new Index();
+
+    return function markDeclaration(node) {
+        const id = generate(node);
+
+        node.id = ids.resolve(id);
+        node.length = id.length;
+        node.fingerprint = null;
+
+        return node;
+    };
+};