Change 'desireable' to 'desirable' per codespell spellchecker.

Author: michaelsafyan

instrumentation-genai/opentelemetry-instrumentation-google-genai/TODOS.md

@@ -18,5 +18,5 @@ Here are some TODO items required to achieve stability for this package:
 
 ## Future
 
-Beyond the above TODOs, it would also be desireable to extend the
+Beyond the above TODOs, it would also be desirable to extend the
 instrumentation beyond `generate_content` to other API surfaces.