WIP: update fmt (>=10.2.1) and spdlog (>=1.13)

[jameslamb]

Description

Contributes to:

• https://github.com/rapidsai/build-planning/issues/54
• https://github.com/rapidsai/build-planning/issues/56
• https://github.com/rapidsai/rapids-cmake/issues/387

Testing with:

• https://github.com/rapidsai/rapids-cmake/pull/592

Will put up a better description and revert testing-only changes before marking this ready for review.

Checklist

• [x] I am familiar with the Contributing Guidelines.
• [x] New or existing tests cover these changes.
• [x] The documentation is up to date with these changes.

[harrism]

Moving to backlog

[jameslamb]

This work is paused, in favor of pursuing a better long-term solution in the future. Closing this PR for now.

Subscribe to https://github.com/rapidsai/build-planning/issues/54 and https://github.com/rapidsai/build-planning/issues/56 for updates.