npm run build:py error on Mac

## Description


## Reproduce

1. Git clone this repo
2. npm run bootstrap
3. npm run build

## Expected behavior

## Context

- JupyterLite version: Version 0.1.2
- Operating System and version: Mac 12.2.1 (21D62)
- Browser and version: Chrome 115.0.5790.170

Browser Output

➜  pyodide-kernel git:(main) ✗ npm run build:py


> @jupyterlite/pyodide-kernel@0.1.1 build:py

> python scripts/generate-wheels-js.py

  File "scripts/generate-wheels-js.py", line 16

    or shutil.which(f"{cmd}.exe")

                               ^

SyntaxError: invalid syntax

npm ERR! Lifecycle script `build:py` failed with error: 

npm ERR! Error: command failed 

npm ERR!   in workspace: @jupyterlite/pyodide-kernel@0.1.1