Don't parse justfile with cookiecutter

cookiecutter.json

@@ -19,6 +19,7 @@
     "__google_sheet_module": "{{ cookiecutter.google_sheet_tabs|lower()|replace(' ', '_')|replace('-', '_') }}",
     "github_token_for_pypi_deployment": "PYPI_PASSWORD",
     "_copy_without_render": [
+        "justfile",
         "src/docs/js/*",
         "src/docs/javascript/*"
     ]