The Elasticsearch transport client has been deprecated since Spring Boot
2.2.0 and is about to be removed from Spring Data Elasticsearch and
Elasticsearch itself in their next major releases.

The available REST client support variants are now the preferred way of
using Elasticsearch features.

Closes gh-19668

See gh-19649

Closes gh-19588

See gh-19588

See gh-19588

See gh-19588

Closes gh-18777

* pr/19464:
  Support nested requests in MetricsClientHttpRequestInterceptor

Closes gh-19464

Prior to this commit, requests made by `HttpRequestInterceptor`
instances configured on `RestTemplate` would not be recorded
properly.

This commit ensures that nested requests are recorded separately.

See gh-19381

Closes gh-19640

Enforcing the spring-boot-dependencies platform makes for too strong
an opinion about the version of Kotlin that should be on the build
script's classpath. It clashes with the version of Kotlin that's
embedded in Gradle and used with Gradle's Kotlin DSL.

This commit switches to a normal platform (rather than an enforced
platform) which allows it to express an opinion about the version of
Kotlin without making it a strict requirement.

Closes gh-19609

Closes gh-19654

See gh-19653

See gh-19651

See gh-19650

This commit removes the validation starter from the web and
webflux starters - we've reconsidered that choice since many were
not using this feature as part of their default web experience.

Thit commit also changes the default EL implementation for the
Jakarta implementation, aligning all servers on it and simplifying
dependency management (especially exclusions that were required
previously).

Closes gh-19550

Closes gh-19630

See gh-19648

See gh-19647

See gh-19646

See gh-19645

See gh-19644

See gh-19643

Closes gh-19630

See gh-19639

See gh-19642

See gh-19641

See gh-19640

Closes gh-19657

Closes gh-19656

Closes gh-19635

* pr/19621:
  Update copyright in legal doc section

Closes gh-19621