Changes for NixOS

[id3v1669]

Changes:

1. Bump flake.lock file as package clap_builder requires newer version of cargo
2. Package swhkd for nix to have ability of direct import
3. Add result folder to gitignore file as it is a build folder of 'nix build'

[Shinyzenith]

Hi I would love to merge this. However, before doing so I'd like to confirm the following:

As a result of our GSoC participation, we are going to refactor the entire security model which will make packaging swhkd easier and also using it. I think it would be ideal to have that merged in instead. In the meantime I am willing to merge this with no maintainance guarantees apart from the basic necessities as I have little to no Nix knowledge.

[id3v1669]

Hi I would love to merge this. However, before doing so I'd like to confirm the following:

As a result of our GSoC participation, we are going to refactor the entire security model which will make packaging swhkd easier and also using it. I think it would be ideal to have that merged in instead. In the meantime I am willing to merge this with no maintainance guarantees apart from the basic necessities as I have little to no Nix knowledge.

My Nix knowledge is also far from advanced as I use it just for a year, but I'm happy to participate as I use swhkd on a daily basis on NixOS.
I plan update packaging for nix when needed.
Later I want to package swhkd in official nix repos and create a module, but for that it would be nice to have more version tags.