Allowlist add releases.nixos.org - #337

What are you trying to accomplish?

I'm trying to fix dependabot/dependabot-core#16479, by adding releases.nixos.org to the egress allowlist.

The problem is that channels.nixos.org 302-redirects to releases.nixos.org breaking automatic updates when tracking channel tarballs.

Anything you want to highlight for special attention from reviewers?

I just added the exact domain to the allowlist. If extra tests for this are required, let me know.

How will you know you've accomplished your goal?

A flake with the following input:

inputs.nixpkgs.url = "https://channels.nixos.org/nixos-unstable/nixexprs.tar.zst";

shows the chain of redirects. With this change I expect everything to resolve to 200 status codes and Dependabot should be able to update these inputs again.

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.