chore(deps): bump springBootVersion from 3.5.5 to 3.5.6 (#890)

Bumps `springBootVersion` from 3.5.5 to 3.5.6.

Updates `org.springframework.boot:spring-boot-starter-webflux` from 3.5.5 to 3.5.6
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.5...v3.5.6)

Updates `org.springframework.boot:spring-boot-starter-oauth2-resource-server` from 3.5.5 to 3.5.6
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.5...v3.5.6)

Updates `org.springframework.boot:spring-boot-starter-oauth2-client` from 3.5.5 to 3.5.6
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.5...v3.5.6)

Updates `org.springframework.boot:spring-boot-starter-test` from 3.5.5 to 3.5.6
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.5...v3.5.6)

Updates `org.springframework.boot:spring-boot-test` from 3.5.5 to 3.5.6
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.5...v3.5.6)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-starter-webflux
  dependency-version: 3.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-starter-oauth2-resource-server
  dependency-version: 3.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-starter-oauth2-client
  dependency-version: 3.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-starter-test
  dependency-version: 3.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-test
  dependency-version: 3.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

build.gradle.kts

@@ -13,7 +13,7 @@ val junitJupiterVersion = "5.13.4"
 val freemarkerVersion = "2.3.34"
 val kotestVersion = "6.0.3"
 val bouncyCastleVersion = "1.82"
-val springBootVersion = "3.5.5"
+val springBootVersion = "3.5.6"
 val reactorTestVersion = "3.7.11"
 val ktorVersion = "2.3.13"
 val jsonPathVersion = "2.9.0"