Merge branch 'release-v1.52'

.ci/scripts/test_old_deps.sh

.github/workflows/docker.yml

.github/workflows/tests.yml

.github/workflows/twisted_trunk.yml

CHANGES.md

debian/changelog

docker/Dockerfile-pgtests

docker/run_pg_tests.sh

docs/MSC1711_certificates_FAQ.md

docs/admin_api/account_validity.md

docs/admin_api/delete_group.md

docs/admin_api/event_reports.md

docs/admin_api/media_admin_api.md

docs/admin_api/purge_history_api.md

docs/admin_api/room_membership.md

docs/admin_api/rooms.md

docs/admin_api/statistics.md

docs/admin_api/user_admin_api.md

docs/admin_api/version_api.md

docs/development/contributing_guide.md