Small tweak to restoring package.json

Co-authored-by: Miguel Fonseca <150562+mcsf@users.noreply.github.com>

Author: youknowriad

tools/gutenberg/build-gutenberg.js

@@ -171,7 +171,7 @@ async function main() {
 async function restorePackageJson() {
 	console.log( '\n🔄 Restoring Gutenberg package.json...' );
 	try {
-		await exec( 'git', [ 'checkout', 'package.json' ], {
+		await exec( 'git', [ 'checkout', '--', 'package.json' ], {
 			cwd: gutenbergDir,
 		} );
 		console.log( '✅ package.json restored' );