Bump @microsoft/api-extractor from 7.12.0 to 7.12.1

Editor assessment

The header `build(deps-dev): bump @microsoft/api-extractor from 7.12.0 to 7.12.1` (with its PR number) states the dependency and the exact version delta, making the change immediately legible without the lockfile. The `build` type and the scope `deps-dev` correctly identifies the affected area correctly frame a routine maintenance upgrade. No body accompanies it; for a dependency bump of this size that omission is acceptable rather than a defect, though the message then offers no rationale for the upgrade. Style is clean — imperative mood, no trailing period, no ticket junk in the subject. Understandable and valid, but a purely mechanical entry with little to teach.