Release v0.15.0-preview.6

What's Changed

• fix(patch): cherry-pick fb99b95 to release/v0.15.0-preview.5-pr-13018 [CONFLICTS] by @gemini-cli-robot in https://github.com/google-gemini/gemini-cli/pull/13022

Full Changelog: https://github.com/google-gemini/gemini-cli/compare/v0.15.0-preview.5...v0.15.0-preview.6