use /usr/bin/env python3 as shebang, to be nice to virtualenv

olasd/consistency/check_objects.py

olasd/consistency/check_swh.py

olasd/consistency/fix_releases.py

olasd/consistency/fix_revisions.py

olasd/consistency/list_origins.py

olasd/github/list_starred_repos.py

olasd/snapshots/create_snapshots.py

seirl/swh-dedup/deduper/__main__.py

sql/anon-dump/anonymize-email

zack/swh-dedup/swh-dedup-blocks.py