[3.14] gh-132775: Unrevert "Use _PyCode GetScriptXIData()"

[ericsnowcurrently]

This reverts commit 7476f90, AKA gh-134600.

This effectively unreverts commit bbf8048 (gh-134515).

I'll merge this once the backport of gh-134686 lands.

• Issue: Improvements to test.support.interpreters.Interpreter #132775

[ericsnowcurrently]

I'm running a refleak buildbot on this (against main) before merging.

[ericsnowcurrently]

!buildbot AMD64 CentOS9 NoGIL Refleaks

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @ericsnowcurrently for commit 1a5a117 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F134736%2Fmerge

The command will test the builders whose names match following regular expression: AMD64 CentOS9 NoGIL Refleaks

The builders matched are:

• AMD64 CentOS9 NoGIL Refleaks PR

[ericsnowcurrently]

!buildbot AMD64 CentOS9 NoGIL Refleaks

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @ericsnowcurrently for commit f4fd092 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F134736%2Fmerge

The command will test the builders whose names match following regular expression: AMD64 CentOS9 NoGIL Refleaks

The builders matched are:

• AMD64 CentOS9 NoGIL Refleaks PR