[3.12] gh-108111: Flush gzip write buffer before seeking, fixing bad writes (GH-108341)#108402

Yhg1s merged 1 commit into

python:3.12python/cpython:3.12from

miss-islington:backport-2eb60c1-3.12miss-islington/cpython:backport-2eb60c1-3.12Copy head branch name to clipboard