fix: disable LiteLLM cache to avoid Redis requirement

Disabled cache setting that requires Redis configuration.
Prompt caching at the Anthropic API level is still enabled
via supports_prompt_caching setting.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

ai/litellm-config.yaml

@@ -30,8 +30,8 @@ model_list:
 litellm_settings:
   drop_params: true
   set_verbose: false  # Disable verbose logging for better performance
-  # Enable prompt caching for better performance
-  cache: true
+  # Disable LiteLLM caching (prompt caching at API level is separate)
+  cache: false
   # Force strip specific parameters globally
   allowed_fails: 0
   # Modify params before sending to provider