Remove Redis from README setup instructions

Redis is no longer needed since the project uses Solid Queue/Cable/Cache.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dadachi

README.md

@@ -23,7 +23,6 @@ Then you can start the database servers:
 
 ```bash
 brew services start postgresql
-brew services start redis
 ```
 
 ## Initial Setup