v6.0.0

What's changed

• Update per Unicode 15.1 by @JLHwung in #81
• [breaking] Always enable unicodeSetsFlag parsing by @JLHwung in #87
• Fix v-flag bugs by @JLHwung in #85
• Fix compiling v set notation to u with unicode properties by @liuxingbaoyu in #70

Full Changelog: v5.3.2...v6.0.0