Revert "Ensure 755 permissions on prebuild spawn-helper"

This reverts commit d08cd36.

Author: devm33

scripts/prebuild.js

@@ -31,12 +31,4 @@ if (!fs.existsSync(PREBUILD_DIR)) {
   process.exit(1);
 }
 
-// Ensure spawn-helper has execute permission (may be stripped by npm pack)
-if (process.platform === 'darwin') {
-  const spawnHelper = path.join(PREBUILD_DIR, 'spawn-helper');
-  if (fs.existsSync(spawnHelper)) {
-    fs.chmodSync(spawnHelper, 0o755);
-  }
-}
-
 process.exit(0);