[Feature]: Add nix substituter settings to flake.nix?

[L-as]

Is there an existing issue for this?

• [X] I have searched the existing issues

Platform

Linux

App version

No response

Feature

I'm trying to build SimpleX (packages.x86_64-linux.aarch64-linux-static:exe:simplex-chat) from source, but it's taking an ungodly amount of time; it seems like it's trying to build GHC, which makes sense if you're using haskell.nix.

I would appreciate it if you could add the settings for the cache to the flake, or alternatively investigate https://github.com/input-output-hk/haskell.nix/issues/1565.