ci: bump pnpm/action-setup from 5.0.0 to 6.1.0 - #4

This extension consists of 1666 files, out of which 923 are JavaScript files. For performance reasons, you should bundle your extension: https://aka.ms/vscode-bundle-extension. You should also exclude unnecessary files by adding them to your .vscodeignore: https://aka.ms/vscode-vscodeignore.