Release r-0842 (v1.4.3)

@aatchison

Info

Commit b77d3e5 was deployed to stage. See code diff.

It was initialized by davinotdavid.

In order to promote this to prod, edit the draft and press "Publish release".

chore(ci): remove legacy IAM CI users — OIDC soak complete (#203) by @aatchison in #1658
Update GitHub templates by @kewisch in #1651
Update fxa-admin-list / APP_ADMIN_ALLOW_LIST envs in stage and prod by @davinotdavid in #1667
Fix LegalView content update toggle + CSS fixes by @davinotdavid in #1669
Bump version to v1.4.3 by @davinotdavid in #1670

Full Changelog: r-0837...r-0842