(2.1.x): Bump org.springframework.boot from 3.1.1 to 3.1.2 (#819)

Bumps [org.springframework.boot](https://github.com/spring-projects/spring-boot) from 3.1.1 to 3.1.2.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.1.1...v3.1.2)

---
updated-dependencies:
- dependency-name: org.springframework.boot
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

settings.gradle

@@ -1,7 +1,7 @@
 pluginManagement {
  plugins {
  id "io.spring.nohttp" version "0.0.11"
- id 'org.springframework.boot' version "3.1.1"
+ id 'org.springframework.boot' version "3.1.2"
  id 'org.asciidoctor.jvm.pdf' version '3.3.2'
  id 'org.asciidoctor.jvm.convert' version '3.3.2'
  }