v0.21.0 protected

Kenta Kabashima

@MusicScience37

7d72c711 · Merge branch 'release-v0.21.0' into 'main' · Feb 10, 2025

Release: v0.21.0

# Release v0.21.0

- Added functions to generate box plots.
- Quit use of `CLOCK_MONOTONIC_RAW` which is less accurate than `CLOCK_MONOTONIC`.
- Updated development environment.