update readme to rm extra installation command.

Author: ParagEkbote

package/callbacks/trackio/README.md

@@ -79,11 +79,6 @@ The callback also supports multi-run mode, where each Optuna trial is tracked as
 
   - Explicitly finalizes synchronization and cleanup after `study.optimize()` completes.
 
-## Installation
-
-```shell
-pip install trackio
-```
 
 ## Example