Fix: #1254, switch to a flake based approach

[YvesStraten]

Pull Request Template

Type of change

• [x] Bug fix
• [ ] Feature
• [ ] Documentation update

Description

This PR aims to fix #1254, allowing ani-cli to be used on Macos with Nix. This PR also switches the shell.nix to a flake.nix, allowing for the following advantages:

1. Ani-cli can now be runned with just nix-run
2. The repo can be added as an input to the flakes of other people
3. Ani-cli is built locally trough nix-build, not relying on the nixpkgs derivation, but the local git repo.

However, it comes with a few caveats due to the fact that nix flakes do not allow for argument passing, e.g --argstr:

1. syncplay and chromecast are installed by default now (adds 10mb to install)
2. There are 2 packages now, one with vcl and one with mpv (Iina is enabled on both of em conditionally depending on platform)

Checklist

• [x] any anime playing

• [ ] bumped version

• [x] next, prev and replay work
• [x] -c history and continue work
• [x] -d downloads work
• [ ] -s syncplay works
• [x] -q quality works
• [ ] -v vlc works
• [x] -e select episode works
• [ ] -S select index works
• [x] -r range selection works
• [ ] --dub and regular (sub) mode both work

• [ ] all providers return links (not necessarily on a single anime, use debug mode to confirm)

• [x] -h help info is up to date
• [x] Readme is up to date
• [x] Man page is up to date

Additional Testcases

[port19x]

Wrong repo imo

https://github.com/NixOS/nixpkgs

[YvesStraten]

are you sure? In that case ill open up a PR there then