fix: deprecate unused SimpleTimer header

[mvanhorn]

Summary

Marks Sofa/framework/Helper/src/sofa/helper/SimpleTimer.h as deprecated using SOFA_HEADER_DEPRECATED. The header has no usages anywhere in the codebase and can be safely deprecated for later removal.

Changes

Sofa/framework/Helper/src/sofa/helper/SimpleTimer.h: Added SOFA_HEADER_DEPRECATED("v26.06", "v27.06", "This header is unused and will be removed.") and included sofa/helper/config.h for the macro definition.

Verified with grep -rn "SimpleTimer" across the entire codebase - no includes or references outside the header file itself.

Fixes #5214

This contribution was developed with AI assistance (Claude Code).

[hugtalbot]

Hi @mvanhorn

Our contribution rules state that:
"While artificial intelligence tools may assist in drafting code contributions, such contributions must address a real issue encountered by a human developer or a feature needed by end users for their specific use case. The contributor must actively participate in the development process from start to finish, ensuring no contribution is fully automated."

Your PR seems to violate this contribution rule. I therefore close this PR.
I let you explain the scope of this work, else I will have to report your account.

Reviewers' time is precious. Such a contribution neglects it.

[mvanhorn]

Hi @hugtalbot, thanks for the feedback. You're right that this was a lightweight change, and I understand the concern about automated contributions consuming reviewer time.

I came across issue #5214 filed by @alxbilger and thought it was a straightforward fix I could help with. I used AI tooling to assist with the implementation but did verify the grep results and the deprecation macro usage myself. That said, I recognize this kind of minimal-touch contribution can feel like noise rather than help, and I appreciate you explaining your expectations.

I'll be more thoughtful about the scope and depth of any future contributions here. Apologies for the wasted review cycle.