See gh-23326

Attempt to fix `ConcurrentModificationException` which occurs on
Java 11+.

See gh-23326

Refactor `BootstrapRegistry` support following initial prototype work
with the Spring Cloud team.

This update splits the `BootstrapRegistry` API into `BootstrapRegistry`,
`BootstrapContext` and  `ConfigurableBootstrapContext` interfaces and
moves it to the same package as `SpringApplication`.

A new `Bootstrapper` interface has been introduced that can be added
to the `SpringApplication` to customize the `BootstrapRegistry` before
it's used.

Closes gh-23326

Move `IncompatibleConfigurationFailureAnalyzer` to fix a package tangle.

Closes gh-23385

Relocate `DefaultPropertiesPropertySource` to fix a package tangle.

Closes gh-23383

Closes gh-23379

Closes gh-23188

Closes gh-23187

Closes gh-23388

Closes gh-23186

Closes gh-23384

Closes gh-23185

Closes gh-23189

Closes gh-23010

Closes gh-23382

Closes gh-23199

Closes gh-23198

* gh-22972:
  Polish "Support authentication to private Docker registry"
  Support authentication to private docker registry

Closes gh-22972

See gh-22972

This commit adds the ability to configure Docker image registry
authentication credentials in the Maven and Gradle plugins. The
authentication credentials are passed to the Docker daemon with
all daemon API calls, and the daemon forwards the credentials to the
image registry when necessary. This makes it possible to use
builder and run images stored in a private Docker registry.

See gh-22972

Closes gh-23378

The version of Spring Boot should not be modifiable by a property,
only being using a different version of spring-boot-dependencies or
spring-boot-starter-parent.

Fixes gh-23174