Argument Clinic: remove the 'version' directive

[erlend-aasland]

Feature or enhancement

The version directive was added in #63929 (Nov 2013), to make it possible for a programmer to require a specific version of Argument Clinic. However, since the "version number" has been hard-coded to "1" since Nov 2013, the version directive has not been used in the CPython code base, and since Argument Clinic is an internal tool, I suggest we remove this feature.

Linked PRs

• gh-113336: Remove the 'version' directive from Argument Clinic #113341