fix: -Wunsafe-buffer-usage warnings in asar file IO (#43650)

* fix: -Wunsafe-buffer-usage warnings in ScopedTemporaryFile::InitFromFile()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* fix: -Wunsafe-buffer-usage warnings in Archive::Init()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

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Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>