tool example has cleanup which is not supported in the actual access-on-demand

### TL;DR

https://github.com/abcxyz/access-on-demand/blob/main/apis/v1alpha1/tool_request.go

There is no such key as cleanup, but the example-tool.yaml includes one.

Either aod needs to be updated to handle cleanup, or the template and all renderings of it should remove it from the example.