flask-security DLA

LTS is experimenting with an issue-based workflow (complementing or replacing data/dla-needed.txt).
See https://gitlab.com/freexian/services/deblts-team/debian-lts/-/issues/47#note_1501889880 for details.

This issue matches the 'flask-security' entry in data/dla-needed.txt.

Goals:

• Encourage better status updates (e.g. more detailed, more frequent)
• Build collaboratively a DLA/ELA check-list to promote high quality updates and avoid regressions
• Have a clearer history (e.g. if there are multiple claims/contributors over time)

Check list pointers:

• bin/package-operations --lts -qp flask-security (gather package info from packages.yml, lts-do-call-me and other sources; also available through ./find-work)
• Development: testing guidelines: https://lts-team.pages.debian.net/wiki/Development.html#test-the-update
• Check-list draft (with more CI-oriented tasks): https://gitlab.com/freexian/services/deblts-team/debian-lts/-/issues/47#note_1464826850

We do not yet have a definite list of items which are expected for each update.
Please perform the update as you would any other LTS/ELTS update, but as you go through the steps consider consulting these links and then documenting in comments to this ticket which items you included or omitted (and also why).