Fix compile warning "Modules/_interpchannelsmodule.c: conversion from 'int64_t' to 'int', possible loss of data"

[sobolevn]

Bug report

Original report by @ByteFlowing1337 #152642 (comment)

[Build CPython: Modules/_interpchannelsmodule.c#L2938]
'function': conversion from 'int64_t' to 'int', possible loss of data [D:\a\cpython\cpython\PCbuild\pythoncore.vcxproj]

Linked PRs

• gh-153444: Fix compile warning in Modules/_interpchannelsmodule.c #153445
• [3.15] gh-153444: Fix compile warning in Modules/_interpchannelsmodule.c (GH-153445) #153447
• [3.14] gh-153444: Fix compile warning in Modules/_interpchannelsmodule.c (GH-153445) #153448
• [3.13] gh-153444: Fix compile warning in Modules/_interpchannelsmodule.c (GH-153445) #153449