Add GitHub Actions workflow for ARM build

[1BigBear]

the official openfang build didn't work for me , didn't even start the init in both the proot-distro ubuntu and the proot-distros termux , so i asked the ai on how to build it for me and we did it (copy paste from ai to GitHub Actions/workflow) because i dont know how to code or even use GitHub actions.
Sooooo at least openfang init worked for me but i still didn't fully test it yet
Anyway
( Everything was made by gpt-5.3-codex, even this description)
The ai made PR

Summary

This updates the release CLI job for aarch64-unknown-linux-gnu to use a native ARM runner (ubuntu-24.04-arm) and removes the cross path for that target.

Why

On Android/proot Ubuntu/Debian environments, the published ARM64 Linux CLI binary failed at runtime due to shared library compatibility issues. Building natively on ARM Linux improves runtime compatibility for glibc-based ARM64 userspace.

Changes

• Switch aarch64-unknown-linux-gnu runner from ubuntu-22.04 to ubuntu-24.04-arm
• Remove cross installation/build branch for ARM64 Linux
• Use standard cargo build --release --target ... --bin openfang for all CLI targets

Validation

• Built ARM64 CLI in GitHub Actions ARM runner
• Installed and ran in Ubuntu proot on Android (openfang --version, openfang init)

[whatnick]

What does did not work mean? Please see #121 which produces working ARM builds which work on Raspberry Pi.

[1BigBear]

@whatnick the build from openfang dev doesn't build openfang for the android os and they as #121 they use old OpenSSL , i dont think if they build with the right OpenSSL it would work, so for me using the PR #161 this would build openfang for the arm devices that are android since openfang dev doesn't build openfang explicitly for android, the PR i provided does work for me and my device, it wasn't meant for raspberry pi, it was meant for android, the PR use ubuntu-arm for the building process that why it would work for the proot-distros in termux, i don't know much about raspberry pi but i know it isn't android aarch64.