Closes gh-20017

Closes gh-20015

This commit upgrades to spring javaformat 0.0.20 and Checkstyle 8.29.

This commit also upgrades to the Checkstyle maven plugin 3.1.0.

See gh-20011

* pr/20002:
  Upgrade to Ant 1.10.7

Closes gh-20002

See gh-20002

Closes gh-20013

* pr/20004:
  Polish samples in doc

Closes gh-20004

See gh-20004

* pr/20009:
  Use Spring 5 module of Jersey

Closes gh-20009

See gh-20009

Closes gh-20010

* pr/20001:
  Polish

Closes gh-20001

See gh-20001

* pr/19995:
  Upgrade copyright date
  Polish

Closes gh-19995

See gh-19995

See gh-19995

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