5.2.1-r0

• Matomo 5.2.1 by @crazy-max in #165
• PHP 8.3 by @crazy-max in #166
• Alpine Linux 3.21 by @crazy-max in #164
• linux/riscv64 platform support by @crazy-max in #167

Full Changelog: 5.1.1-r1...5.2.1-r0