* Support building free-threaded CPython
Add support for Python's free threading build mode where the global
interpreter lock is disabled. The packages are marked using a suffix on
the architecture, like 'x64-freethreaded' or 'arm64-freethreaded'.
* Match '-freethreaded' in arch
* Use type 'string' instead of 'str'
* On Linux, only delete Python installations with the same architecture.
This matches the macOS behavior and allows users to install both the
free-threading and default builds at the same time.
