See gh-19860

Fixes gh-19973

Layers were being added to the EphemeralBuilder each time one was
created, but those layers already existed in the base builder image.

Closes gh-19832

Closes gh-19912

Closes gh-19989

Closes gh-19932

Closes gh-19934

Closes gh-19945

Fixes gh-19964

* pr/19985:
  Polish "Use new AssertJ duration assertions"
  Use new AssertJ duration assertions
  Upgrade to AssertJ 3.15.0

Closes gh-19985

See gh-19985

See gh-19985

See gh-19985

Previously, the image builder used by the build tool plugins ignored
errors from lifecycle phases and continued with subsequent phases.

This commit inspects the status of the builder container after each
lifecycle phase and aborts the image building process if the exit
status of the container after any phase is non-zero.

Fixes #19949

Closes gh-19977

* pr/19976:
  Update test name in WebFluxTagsTests

Closes gh-19976

See gh-19976

See gh-19802

Closes gh-19971

Closes gh-19970

Previously, only the top-level handlers were examined to find the
ContextHandlers and log the context path. If those handlers had
been wrapped, this prevented the ContextHandlers from being found
and an empty string was always logged.

When finding the context path, this commit unwraps the handler held
by a HandlerWrapper until the ContextHandler is found.

Fixes gh-19969

For consistency with SpringApplication, this commit disables bean
overriding by default in ApplicationContextRunner. Bean overriding can
be enabled again using withAllowBeanDefinitionOverriding.

Closes gh-18019

* pr/19864:
  Use Supplier variants of Assert

Closes gh-19864

See gh-19864

Closes gh-19966

Closes gh-19965

* pr/19961:
  Fix Gradle plugin documentation links

Closes gh-19961

See gh-19961

Closes gh-19963

Closes gh-19962

* pr/19944:
  Replace deprecated Concourse resource for pull requests

Closes gh-19944

See gh-19944

* pr/19899:
  Polish "Fix scope of CqlSessionBuilder bean"
  Fix scope of CqlSessionBuilder bean

Closes gh-19899

See gh-19899