x.py: env python no longer available in macos monterey 12.3

[Walther]

macOS Monterey 12.3 was released today.

The release notes include:

Python

Deprecations

• Python 2.7 was removed from macOS in this update. Developers should use Python 3 or an alternative language instead. (39795874)

The x.py tool used for the development process of the compiler starts with the line

#!/usr/bin/env python

On macOS Monterey 12.3, running env python results in

env: python: No such file or directory

It would probably be the time to make the script require Python 3, with

#!/usr/bin/env python3

See also #71818 for older context.

[Mark-Simulacrum]

I'm going to close this in favor of #71818, which seems like still the right issue to track this problem; I don't think this release significantly changes the calculus in my eyes. An updated summary for various platforms would be great to post on that issue though (e.g., including https://bugs.python.org/issue46645 as a link).