prefect 3.0.0rc20 on Python PyPI

What's Changed

allow JSON values in Secret block by @zzstoatzz in #14980
Workers enforce Deployment.concurrency_limits by @jeanluciano in #15022
Improve logging on result serialization errors by @desertaxle in #15084
record task run followers by @jakekaplan in #15100
Switch to profile with matching PREFECT_API_URL on server start by @desertaxle in #15122

Revert change to defer building the server-side version of PrefectBaseModel by @desertaxle in #15072
Fixes prefect server start for Windows machines by @desertaxle in #15103
Fix CloudUnauthorized case in prefect dashboard open by @zzstoatzz in #15106
ensure on_failure hook runs upon parameter validation error by @zzstoatzz in #15109
Update model_rebuild in main.py to explicitly pass namespace types by @desertaxle in #15117

Avoid result factories if persistence is turned off for a task by @cicdw in #15055
Remove UnpersistedResult by @cicdw in #15056
Replace PersistedResultBlob with ResultRecord by @desertaxle in #15064
Update @prefecthq/prefect-ui-library to version 3.7.2 by @marvin-robot in #15082
a couple typing and error improvements by @zzstoatzz in #15081
Bump vite from 5.4.1 to 5.4.2 in /ui by @dependabot in #15068
Bump micromatch from 4.0.5 to 4.0.8 in /ui by @dependabot in #15083
Update @prefecthq/prefect-ui-library to version 3.7.3 by @marvin-robot in #15097
Updates warning message when result persistence fails by @desertaxle in #15099
fix typing and docstring for concurrency ctx managers by @zzstoatzz in #15108
Remove unused Manifest class by @desertaxle in #15111
Update @prefecthq/prefect-ui-library to version 3.7.5 by @marvin-robot in #15116
Update @prefecthq/prefect-ui-library to version 3.7.6 by @marvin-robot in #15125
Update @prefecthq/prefect-ui-library to version 3.7.7 by @marvin-robot in #15126
annotation type fixes by @zzstoatzz in #15124

Test experimental_defer_build_mode with defer_build=True by @abrookins in #15052
Readme updates: formatting typo and messaging updates by @sarahmk125 in #14952
bugfix for sorting scheduled flow_runs by @tmylt in #14993
Add whats new and upgrade guide by @jlowin in #14996
add prefect dashboard open to open dashboard from CLI by @zzstoatzz in #14985
simplify on_crash hook example by @zzstoatzz in #15079
improve Manage concurrency docs by @zzstoatzz in #15088
Quotes the components of a PostgreSQL connection URL when built from components by @chrisguidry in #15094
minor docs formatting fixes by @zzstoatzz in #15105
Update artifacts doc page by @discdiver in #15093
Update language in quickstart by @cicdw in #15115
Update write tasks page for clarity by @desertaxle in #15118
Updates to logging page for clarity by @desertaxle in #15119
Go through contributing docs by @cicdw in #15120
Add Prefect Cloud IP Allowlist CLI by @collincchoy in #15087
bubble up hydration placeholders by @jakekaplan in #15132
Update work pools doc for flow and clarity by @desertaxle in #15127

Full Changelog: 3.0.0rc19...3.0.0rc20