fix miniflare sidebar order (#21606)

Author: emily-shen

src/content/docs/workers/testing/miniflare/index.mdx

@@ -2,7 +2,7 @@
 title: Miniflare
 pcx_content_type: navigation
 sidebar:
-  order: 1
+  order: 16
 head:
   - tag: title
     content: Miniflare