Allow GitHub.com in restrict-eval

.github/workflows/build.yml

@@ -42,6 +42,7 @@ jobs:
       run: |
         nix-env -f . -qa \* --meta --xml \
           --allowed-uris https://static.rust-lang.org \
+          --allowed-uris https://github.com \
           --option restrict-eval true \
           --option allow-import-from-derivation true \
           --drv-path --show-trace \