gh-143241: Fix infinite loop in `zoneinfo._common.load_data` (#143243)

Correctly reject truncated TZif files in `ZoneInfo.from_file`.

---------

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>