nix: make dist tarball in nix

This is more sound than having to rely on host nix shell.

Signed-off-by: Ophestra <cat@gensokyo.uk>

.gitea/workflows/static.yml

@@ -27,7 +27,7 @@ jobs:
         run: >-
           export HAKUREI_REV="$(git rev-parse --short HEAD)" &&
           sed -i.old 's/version = /version = "0.0.0-'$HAKUREI_REV'"; # version = /' package.nix &&
-          nix build --print-out-paths --print-build-logs .#hakurei-static &&
+          nix build --print-out-paths --print-build-logs .#static &&
           mv package.nix.old package.nix &&
           echo "rev=$HAKUREI_REV" >> $GITHUB_OUTPUT