AAC codec plugin for Raspberry Pi OS 64bit

As we all know Debian 12 switched to pipewire as audio backend, and the crew haven't decided to move fdk-aac out of non-free repo.

So by default install, there is no AAC codec for bluetooth, but it can be manually build from source.

Then there is the aac codec plugin, install steps:

1. Make sure you are using PipeWire audio backend in raspi-config
2. Install libfdk-aac2: sudo apt install libfdk-aac2
3. Download the libspa-codec-bluez5-aac.so
4. Move it into /usr/lib/aarch64-linux-gnu/spa-0.2/bluez5
5. Reboot
6. Connect your Apple AirPods (any)
7. Enjoy

This so is built in libspa-0.2-bluetooth_0.3.65-3 and Debian 12 (bookworm)