Include `aria2c` on a-shell mini

[bbb651]

aria2c is needed for downloading in ani-cli, and seems useful to have in general e.g. it’s an optional dependency for yt-dlp.

I think it has to be included with a-shell rather than be an optional wasm package, due to:

• It looks harder to build for wasm compared to existing successful iOS builds
• It’s potentially performance sensitive, on iSH downloads are really slow due to the linux emulation (although wasm probably isn’t as bad, will also help with battery life)
• I think pretty useful to have by default on a-shell mini for ani-cli/yt-dlp use cases

I found an iOS build script targeting jailbroken devices, I think it should mostly work for a-shell as well.

[holzschu]

I think I remember aria2c being requested before; It seems to be licensed under the GPL, which means the FSF says it cannot be included in the AppStore version. Compiling it to WebAssembly is the only way forward (and it's going to be challenging).