Use a github token if possible

To prevent some API limiting

.github/workflows/test.yml

@@ -26,7 +26,7 @@ jobs:
     - run: |
         cachix use nixos-nix-install-tests
         CURRENT_NIX_BUILD=$(nix-build -A defaultPackage.$(nix-instantiate --eval -E '(builtins.currentSystem)'))/bin
-        PATH=$CURRENT_NIX_BUILD:$PATH bash scripts/test-against-master.sh
+        PATH=$CURRENT_NIX_BUILD:$PATH GITHUB_TOKEN=${{ secrets.GITHUB_TOKEN }} bash scripts/test-against-master.sh
   check_cachix:
     name: Cachix secret present for installer tests
     runs-on: ubuntu-latest

scripts/test-against-master.sh

@@ -7,6 +7,10 @@ CurrentNixDir=$(pwd)
 CurrentRev=${GITHUB_SHA:-$(git rev-parse HEAD)}
 WorkDir=$(mktemp -d)
 trap 'rm -r "$WorkDir"' EXIT
+GITHUB_TOKEN_OPTION=()
+if [[ -n "${GITHUB_TOKEN:-}" ]]; then
+    GITHUB_TOKEN_OPTION=("--option" "access-tokens" "github.com=$GITHUB_TOKEN")
+fi
 
 pushd "$WorkDir"
 
@@ -22,6 +26,8 @@ cat <<EOF > flake.nix
     };
 }
 EOF
-nix --experimental-features 'nix-command flakes' flake check
+nix flake check\
+    --experimental-features 'nix-command flakes' \
+    "${GITHUB_TOKEN_OPTION[@]}"
 
 popd