Closes gh-11745

* pr/11775:
  Upgrade to Maven Checkstyle Plugin 3.0.0

Closes gh-11775

Closes gh-8933

There's an extra ClassLoader in the hierarchy of the TCCL in Groovy
2.4 vs Groovy 2.5 so we require an extra getParent() call to avoid
being able to load classes that are visible to the launched URL
class loader.

Closes gh-11745

Closes gh-9980

Closes gh-11771

This reverts commit 8619256d.

See gh-11676

Closes gh-11756

Closes gh-11770

Closes gh-11573

Previously, the logging system was cleaned up in response to the
root context's ContextClosedEvent being received. This event is
published early in a context's close processing. As a result, the
logging system is in cleaned up state while, for example, disposable
beans are being destroyed.

This commit reworks the logic that triggers logging system clean up
to use a disposable bean instead. Disposable beans are called in
reverse-registration order. The logging clean up bean is registered as
early as possible so that it should be the last disposable bean to
be called.

Closes gh-11676

Closes gh-11573

Update `@SpringBootTest` `WebTestClient` support so that the bean
definition is only registered when the user has not defined or
auto-configured their own.

See gh-10556

Update `@SpringBootTest` `TestRestTemplate` support so that the bean
definition is only registered when the user has not defined or
auto-configured their own.

See gh-10556

Move the "testdb" naming logic to `DataSourceProperties` and expose
the `deduceDatabaseName` method so they can be used in
auto-configuration.

See gh-11719

Previously, Hikari's pool name was auto-configured with the value of
`spring.datasource.name` that defaults  to `testdb`, which brings some
confusion.

This commit removes the default `testdb` value on
`spring.datasource.name` as it is a sane default only for an embedded
datasource. It is applied whenever applicable instead.

Closes gh-11719

Add first class support for Servlet based endpoints and rework the
Jolokia endpoint to use it.

Fixes gh-10264

* pr/11759:
  Remove usage of Vector collection

Closes gh-11759

Closes gh-11754

Closes gh-11754
See gh-11684

Replace regular Map instances with EnumMap to reduce memory consumption.

Closes gh-11760

Rename packages and classes to match the new module name.

See gh-11301

On CI, Cassandra running inside the Docker container sometimes fails
to start or the start times out. This has nothing to do with Boot so
we  attempt to protect our tests from the flakiness of the container
by allowing 3 startup attempts.

Closes gh-11757

Closes gh-11666

Closes gh-11673

Rename `spring-boot-deprecated-properties-support` to
`spring-boot-properties-migrator`.

See gh-11301

* pr/11744:
  Polish "Add support for anonymousReadOnly in LdapProperties"
  Add support for anonymousReadOnly in LdapProperties
  Move tests to use ApplicationContextRunner

Closes gh-11744

See gh-11744