AARCH64 Version / RPI4B

Pasting my recipe for an aarch64 build on a RPI4B running standard OS based on Debian 13.

Not sure if this is mainstream enough, but please consider offering an AARCH64 Version each main release.

Requirements via apt, npm and gem.

```
sudo apt install nodejs npm yarnpkg python3-setuptools ruby libarchive-tools rpm
sudo npm install --global yarn
sudo gem install fpm
```

Standard git clone
```
git clone --recursive https://github.com/ExpressLRS/ExpressLRS-Configurator.git
cd ExpressLRS-Configurator/
```

build process, the symbol is required because yarn tries with the armhf fpm instead of aarch64 fpm
```
export USE_SYSTEM_FPM=true
yarn install --prefer-offline
yarn build
yarn electron-builder --arm64 --linux --publish never
```