Avoid Spring AI MCP warning

[johnsonr]

We get a lot of warnings like this:

2025-12-21T15:28:06.586+10:00 INFO 80717 --- [drivine4j] [mcat-handler-32] o.springframework.ai.tool.ToolCallback : By default the tool context is not used, override the method 'call(String toolInput, ToolContext toolcontext)' to support the use of tool context.Review the ToolCallback implementation for shepherd_git_listFiles

This does not indicate an issue with Embabel as we don't use the Spring AI tool context mechanism.

It would be good to avoid this warning confusing users.