Previously, ErrorPageFilter's ErrorResponseWrapper would delaying
sending an error back to the client. In cases where the response's
Writer or OutputStream was accessed and flushed or closed, this could
lead to the wrong response status being sent.

This commit updates ErrorResponseWrapper so that it will send any
capture error to the client before returning the response's Writer or
OutputStream. This ensures that closing the Writer or OutputStream
does not cause the response to be committed with the default response
status rather than the previously captured error status.

Such responses will now include the correct status, but will not be
forwarded to the error controller. Such forwarding is not possible
due to the response already having been committed.

Closes gh-11814

Closes gh-12681

This commit ensures that `WebFluxTags` not only relies on
`BEST_MATCHING_PATTERN_ATTRIBUTE` or request URI to provide the "uri"
tag information.

To avoid cardinality explosion, HTTP not found and redirects are
assigned fixed uri tags.

Closes gh-12685

Closes gh-12750

Closes gh-12739

Fixes gh-12728

Closes gh-12340

Closes gh-12698

Closes gh-12344

See if that fixes intermittent NoClassDefFoundError.

See gh-12689

Closes gh-12748

Closes gh-12746

Closes gh-12745

Closes gh-12744

Closes gh-12734

Closes gh-12736

Closes gh-12735

* pr/12711:
  Remove outdated reference to `EnvironmentTestUtils`

Documentation still refers to the now deprecated `EnvironmentTestUtils`
class instead of `TestPropertyValues` for setting environment values in
tests.

This commit replaces it with `TestPropertyValues` and provides an
equivalent code example.

Closes gh-12711

* gh-12715:
  Polish "Use modifiable set for @ServletComponentScan with no packages"
  Use modifiable set for @ServletComponentScan with no packages

Closes gh-12715

Previously, when a project contained multiple `@ServletComponentScan`
annotated classes in classpath, and at least one annotation don't
explicitly specify `basePackages` and `basePackageClass` attribute,
the application could fail to start with an
UnsupportedOperationException. The failure occurred due to the
creating of an unmodifiable set when no base packages are configured
and a subsequent attempt to add base packages to that sit.

This commit fixes the issue by removing the use of an unmodifiable set
when `@ServletComponentScan` with no base packages in processed before
any other `@ServletComponentScan` annotations.

See gh-12715

This commit updates WebTestClientAutoConfiguration to only create a
WebTestClient when running a WebFlux-based application as mocking the
context only works with that mode at the moment.

Closes gh-12318

* pr/12683:
  Polish "Remove HierarchicalNameMapper as a configured @Bean"
  Remove HierarchicalNameMapper as a configured @Bean

Closes gh-12683

HierarchicalNameMapper is not a component that can be shared amongst
multiple monitoring systems.

See gh-12683

Closes gh-12557

* pr/12725:
  Remove destroyMethod attribute in @Bean for MeterRegistry

Closes gh-12725

Closes gh-12731

Closes gh-12730