3.6.16.dev5: Nightly Development Release

What's Changed

Fix visit_collection to handle NamedTuples by @chuqCTC in https://github.com/PrefectHQ/prefect/pull/20517
fix(ui): use count endpoint for deployments page empty state check by @zzstoatzz in https://github.com/PrefectHQ/prefect/pull/20404

migrate prefect-gcp secret_manager from @sync_compatible to @async_dispatch by @zzstoatzz in https://github.com/PrefectHQ/prefect/pull/20513

Remove old admin routes by @desertaxle in https://github.com/PrefectHQ/prefect/pull/20515
Split prefect-sqlalchemy into SqlAlchemyConnector (sync) and AsyncSqlAlchemyConnector (async) by @devin-ai-integration[bot] in https://github.com/PrefectHQ/prefect/pull/20447

Add tests/infrastructure to clear_db exclusion list by @devin-ai-integration[bot] in https://github.com/PrefectHQ/prefect/pull/20507
Fix flaky test: add thread completion check and increase timeout by @devin-ai-integration[bot] in https://github.com/PrefectHQ/prefect/pull/20505
Fix env var template resolution in deploy --all console output by @devin-ai-integration[bot] in https://github.com/PrefectHQ/prefect/pull/20511
Add bulk operation endpoints for flow runs, deployments, and flows by @bunchesofdonald in https://github.com/PrefectHQ/prefect/pull/20469
fix: resolve circular import when plugins import from prefect by @desertaxle in https://github.com/PrefectHQ/prefect/pull/20514

@chuqCTC made their first contribution in https://github.com/PrefectHQ/prefect/pull/20517

Full Changelog: https://github.com/PrefectHQ/prefect/compare/3.6.16.dev4...3.6.16.dev5