Bump org.springframework.boot from 3.5.8 to 3.5.9

Bumps [org.springframework.boot](https://github.com/spring-projects/spring-boot) from 3.5.8 to 3.5.9.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.8...v3.5.9)

---
updated-dependencies:
- dependency-name: org.springframework.boot
  dependency-version: 3.5.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

build.gradle.kts

@@ -15,7 +15,7 @@ plugins {
     id("io.freefair.aspectj.post-compile-weaving") version "9.1.0"
     // id("io.freefair.maven-central.validate-poms") version "9.0.0" // TODO: Re-enable when compatible with Gradle 9
     id("com.github.ben-manes.versions") version "0.53.0"
-    id("org.springframework.boot") version "3.5.8"
+    id("org.springframework.boot") version "3.5.9"
     id("io.spring.dependency-management") version "1.1.7"
     id("io.sentry.jvm.gradle") version "5.12.2"
     id("io.github.1c-syntax.bslls-dev-tools") version "0.8.1"