fix(better-auth): revert back to version 1.2.9 (#1352)

Author: icecrasher321

apps/sim/package.json

@@ -31,7 +31,7 @@
     "@aws-sdk/s3-request-presigner": "^3.779.0",
     "@azure/communication-email": "1.0.0",
     "@azure/storage-blob": "12.27.0",
-    "@better-auth/stripe": "1.3.10",
+    "@better-auth/stripe": "1.2.9",
     "@browserbasehq/stagehand": "^2.0.0",
     "@cerebras/cerebras_cloud_sdk": "^1.23.0",
     "@chatscope/chat-ui-kit-react": "2.1.1",
@@ -75,7 +75,7 @@
     "@vercel/og": "^0.6.5",
     "@vercel/speed-insights": "^1.2.0",
     "ai": "^4.3.2",
-    "better-auth": "1.3.10",
+    "better-auth": "1.2.9",
     "browser-image-compression": "^2.0.2",
     "cheerio": "1.1.2",
     "class-variance-authority": "^0.7.1",