_decimal_Context_apply_impl applies to a non-defined variable v, not x

[AZero13]

Bug report

Bug description:

This is only applicable to enhanced_functionality.

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

Linked PRs

• gh-142440: apply context to x, not v, in _decimal_Context_apply_impl #142441

[serhiy-storchaka]

Thank you for your contribution @AZero13. This was a 3.15 only bug.