fix: await async generateRss/checkDataFromAlgolia in getStaticProps (notionnext-org#3992)

`generateRss` and `checkDataFromAlgolia` are both async functions,
but they were called without `await` inside `getStaticProps`. This
creates a race condition where the build process may finish and
proceed to deployment before the RSS files (public/rss/feed.xml,
atom.xml, feed.json) are actually written to disk.

Contrast with `generateRobotsTxt` and `generateSitemapXml` which
are synchronous and complete immediately — they are unaffected.

Symptoms:
- RSS feed returns 404 or corrupted content after deployment
- The issue is non-deterministic (depends on how many posts need
  Notion API calls and whether the build finishes first)
- More likely to manifest in CI/CD environments where the build
  completes quickly and immediately copies artifacts

Root cause in generateRss:
- For each post, it calls `await getPostBlocks(post.id, 'rss-content')`
  to fetch content from the Notion API
- Then renders each post via `ReactDOMServer.renderToString()`
- Finally writes feed.xml / atom.xml / feed.json to public/rss/
- Without `await`, getStaticProps returns before any of this completes

The fix simply adds `await` to both calls so getStaticProps waits
for file generation to complete before returning.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: xueayi

pages/index.js

@@ -91,11 +91,11 @@ export async function getStaticProps(req) {
     // 生成robotTxt
     generateRobotsTxt(props)
     // 生成Feed订阅
-    generateRss(props)
+    await generateRss(props)
     // 生成
     generateSitemapXml(props)
     // 检查数据是否需要从algolia删除
-    checkDataFromAlgolia(props)
+    await checkDataFromAlgolia(props)
     if (siteConfig('UUID_REDIRECT', false, props?.NOTION_CONFIG)) {
       // 生成重定向 JSON
       generateRedirectJson(props)