chore: bump @genkit-ai/firebase version to @genkit-ai/firebase@1.9.1-rc.0

Author: Automated Version Bump

js/plugins/firebase/package.json

@@ -13,7 +13,7 @@
     "genai",
     "generative-ai"
   ],
-  "version": "1.9.0",
+  "version": "1.9.1-rc.0",
   "type": "commonjs",
   "scripts": {
     "check": "tsc",