Closes gh-21889

Closes gh-21783

Closes gh-21888

Closes gh-21781

Closes gh-21887

Closes gh-21886

Closes gh-21780

See gh-21885

This commit aligns log4j2's behavior with logback such that loggers
with a null configuredLevel are also returned by the actuator endpoint.

Fixes gh-20037

Fixes gh-21293

See gh-21716

Update the pipeline YAML to use ((milestone)) rather than ((branch))
when tagging docker images.

See gh-21716

Closes gh-21876

Use YAML anchors and aliases to reduce the amount of repetition
in our CI pipeline YAML.

Closes gh-21716

This commit updates the logic for handling binding exceptions in the
management context when it is separate from the application context.
The changes allow the exception details to be visible to
DefaultErrorAttributes without causing the servlet container to
detect an error condition.

Fixes gh-21036

Closes gh-21778

Closes gh-21775

Closes gh-21774

Closes gh-21777

Closes gh-21838

Closes gh-21836

Closes gh-21835

Closes gh-21834

Closes gh-21833

Closes gh-21832

Closes gh-21831

Closes gh-21830

Closes gh-21829

Closes gh-21828