[TASK] Clean up robots.txt

Related: T3DEMO-301

config/sites/main/config.yaml

@@ -52,7 +52,7 @@ routes:
   -
     route: robots.txt
     type: staticText
-    content: "User-agent: *\r\nDisallow: /typo3/\r\nAllow: /typo3/sysext/frontend/Resources/Public/*\r\n\r\nUser-Agent: *\r\nDisallow: /*_staff* \r\n\r\nSitemap: https://demo.typo3.org/sitemap.xml"
+    content: "User-agent: *\r\nDisallow: /typo3/\r\nAllow: /typo3/sysext/frontend/Resources/Public/*\r\n\r\nSitemap: https://demo.typo3.org/sitemap.xml"
 routeEnhancers:
   PageTypeSuffix:
     type: PageType