Update auto-label version (#6435)

Author: stevejgordon

.github/auto-label.json

@@ -1,6 +1,6 @@
 {
   "rules": {
     "Infra": [".ci/**/*", ".github/**/*","build/**/*"],
-    "v9.0.0-alpha.1": "**/*"
+    "v8.4.0-alpha.1": "**/*"
   }
 }