fix: add -s flag to xattr command to skip symlinks in macOS CI builds

The xattr command was failing in CI when encountering pnpm symlinks
that point to non-existent store locations. Adding the -s flag tells
xattr to skip symbolic links, preventing "No such file" errors while
still clearing extended attributes from actual files.

This fixes macOS CI build failures without affecting the intended
functionality of removing quarantine and other extended attributes.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: holmesworcester

.github/workflows/desktop-build.yml

@@ -257,7 +257,7 @@ jobs:
           source-path: darwin
 
       - name: "Remove crud files"
-        run: xattr -cr .
+        run: xattr -crs .
 
       - name: "Set electron-builder props"
         run: echo "ELECTRON_BUILDER_PROPS=-c.publish.bucket=$S3_BUCKET" >> $GITHUB_ENV