fix(nix): simplify --extra-experimental-features argument (#32289)

lib/modules/manager/nix/artifacts.spec.ts

@@ -36,17 +36,14 @@ process.env.CONTAINERBASE = 'true';
 const config: UpdateArtifactsConfig = {};
 const lockMaintenanceConfig = { ...config, isLockFileMaintenance: true };
 const updateInputCmd = `nix \
-    --extra-experimental-features nix-command \
-    --extra-experimental-features flakes \
+--extra-experimental-features 'nix-command flakes' \
 flake lock --update-input nixpkgs`;
 const updateInputTokenCmd = `nix \
-    --extra-experimental-features nix-command \
-    --extra-experimental-features flakes \
+--extra-experimental-features 'nix-command flakes' \
 --extra-access-tokens github.com=token \
 flake lock --update-input nixpkgs`;
 const lockfileMaintenanceCmd = `nix \
-    --extra-experimental-features nix-command \
-    --extra-experimental-features flakes \
+--extra-experimental-features 'nix-command flakes' \
 flake update`;
 
 describe('modules/manager/nix/artifacts', () => {

lib/modules/manager/nix/artifacts.ts

@@ -22,9 +22,7 @@ export async function updateArtifacts({
     return null;
   }
 
-  let cmd = `nix \
-    --extra-experimental-features nix-command \
-    --extra-experimental-features flakes `;
+  let cmd = `nix --extra-experimental-features 'nix-command flakes' `;
 
   const token = findGithubToken(
     hostRules.find({