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  Remove outdated reference to `EnvironmentTestUtils`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

* pr/12722:
  Add space between right parentheses and next word

Closes gh-12722