Mirroring `nixos-yymm-small`

[thefossguy]

For flakes that I use for devShells, I'd prefer to use the nixos-$release-small branch of nixpkgs. Specifically because they get faster patches than the normal channels and it's good to have that peace of mind for something used at work. :)

I'm happy to send a PR, but I'm not sure how the semantic versioning for that branch might look and this issue is to track exactly that.

Given, nixos-unstable = 0.1.x and nixos-yy.mm = 0.yymm.x., is nixos-yymm-small = 0.2.yymm.x. okay?

[thefossguy]

I'm so stupid, went for a walk and I'm back with 0.yymm-small.x.. This should be better. Waiting on input :)

diff --git a/.github/workflows/nixpkgs.yml b/.github/workflows/nixpkgs.yml
index 2988aad..1b68172 100644
--- a/.github/workflows/nixpkgs.yml
+++ b/.github/workflows/nixpkgs.yml
@@ -28,7 +28,7 @@ jobs:
                 process.exit(1);
             }
             console.log(`Calculating the minor version for ${ref}`);
-            let regex = new RegExp(/^nixos-(?<version>([0-9]+\.[0-9]+)|unstable)$/);
+            let regex = new RegExp(/^nixos-(?<version>([0-9]+\.[0-9]+)(-small)?|unstable)$/);
             let match = regex.exec(ref);
             if (match && match.groups) {
                 const versionPart = match.groups.version;