v9.0.0

Breaking

• Remove the embedded methods: and ruby: blocks from all region files. Method bodies now live in each consuming library; function: and observed: names are unchanged. See doc/SYNTAX.md. definitions pull-382, definitions pull-383, definitions issue-379
  Non-breaking (results may change for the listed regions; no consumer code change needed)
• Add cn China statutory national holidays, with year ranges for the 2008 and 2025 reforms. 调休 make-up workdays are not modelled. definitions pull-370, definitions issue-112
• Fix jp substitute holidays ignoring year_ranges, which made the 2019-only Reiwa accession dates recur every year. definitions pull-368, holidays issue-366
• Fix kr 설날 연휴 (Seollal eve) resolving to the wrong year; now derived as the day before 설날. definitions pull-371, holidays issue-388
• Fix nz_sl Southland Anniversary Day to Easter Tuesday and nz_hb Hawke's Bay Anniversary Day to the Friday before Labour Day. definitions pull-375, definitions issue-260
• Restrict ro Boboteaza and Soborul Sfântului Ioan Botezătorul to 2024 onwards. definitions pull-373, definitions issue-296
• Extend tr Ramazan and Kurban Bayramı through 2030. definitions pull-376, definitions pull-378, definitions issue-377
• Add de_be Tag der Befreiung on 8 May 2025. definitions pull-293 (thanks to https://github.com/michaelem)
• Add informal Day of the Dead for us and ca on 1 and 2 November. definitions pull-374, holidays issue-393
• Add a de_mv Internationaler Frauentag boundary test. definitions pull-372
• Fix a th test date typo. definitions pull-381