chore: upgrade to react-email 6 (#64)

Author: joaopcm

package.json

@@ -6,10 +6,10 @@
     "lint": "biome check ."
   },
   "dependencies": {
-    "@react-email/render": "2.0.0",
     "hono": "4.8.4",
     "react": "19.1.0",
     "react-dom": "19.1.0",
+    "react-email": "6.0.0",
     "resend": "6.5.2"
   },
   "devDependencies": {