chore(area-data): use Rslib to build (#13251)

packages/vant-area-data/rslib.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from '@rslib/core';
+
+export default defineConfig({
+  lib: [
+    { format: 'esm', syntax: ['Chrome 53'], dts: true },
+    { format: 'cjs', syntax: ['Chrome 53'] },
+  ],
+  output: {
+    target: 'web',
+  },
+});