* pr/11486:
  Update copyright header
  Remove unnecessary condition in ConfigurationPropertyName

Closes gh-11486

This commit fixes the `responseCommitted` test in
`DefaultErrorWebExceptionHandlerIntegrationTests` and reworks the whole
test class to use the `ContextRunner` infrastructure.

Fixes gh-11519

This commit removes
`RestTemplateBuilder.requestFactory(ClientHttpRequestFactory factory)`
because it can be misleading. This builder class is meant to be
immutable, but calling that method and then timeout related ones will
affect the `ClientHttpRequestFactory` instance.

Instead, this method is replaced with a
`Supplier<ClientHttpRequestFactory>` that is called every time a
`RestTemplate` is being built.

That approach may reduce the reusability of request factories, but it is
much more consistent.

Closes gh-11255

* pr/11502:
  Polish "Add support for additional Kafka listener properties"
  Add support for additional Kafka listener properties

Closes gh-11502

See gh-11502

* pr/11492:
  Polish "Deduplicate tag values in metrics actuator endpoint"
  Deduplicate tag values in metrics actuator endpoint

Closes gh-11492

See gh-11492

This is no longer necessary as of micrometer 1.0 rc5

See gh-11520

As HibernateJpaConfiguration is package private, it is no longer
possible to extend the default Spring Boot configuration to apply
advanced settings. The most notable use case for this is the
customization of Hibernate properties using instance value vs. string
value that can be set using the "spring.jpa.properties" namespace.

This commit adds a HibernatePropertiesCustomizer callback interface that
can be implemented to tune Hibernate properties at will.

Closes gh-11211

Closes gh-11508

See gh-11510

* pr/11510:
  Polish

Closes gh-11510

Fixes gh-11383

See gh-10516

Fixes gh-10516

See gh-11503

See gh-11501

This reverts commit f91f8f7e.

See gh-11475

* pr/11489:
  Polish
  Full editing pass plus linking

I made a complete editing pass plus another pass to see where I could add more links, both within the document and to other parts of Spring. The result was a thorough edit (though I'm sure I missed things, purely due to the size of the thing).

Closes gh-10133

Closes gh-11490