packaging(apk): add armv7l to APKBUILD (Alpine armhf)

[satwareAG-ironMike]

Context

Add armv7l to the Alpine APKBUILD for Alpine ARM (e.g. Raspberry Pi running Alpine).

Acceptance Criteria

• packaging/apk/APKBUILD adds armv7l to arch line
• Build runs via QEMU on alpine:3.21 armhf rootfs
• .apk produced: php84-pecl-firebird-13.0.0-r0.armv7l.apk
• Package installs and loads on Alpine armhf

Dependencies

• Bug: Segfault in transaction cleanup after fbird_drop_table_force (migration_001) #13 (APKBUILD)

Suggested Test Plan

1. Build via QEMU armhf
2. Install on Alpine 3.21 armhf
3. php84 -m | grep firebird — loaded