Bump springBootVersion from 3.1.3 to 3.2.1

Bumps `springBootVersion` from 3.1.3 to 3.2.1.

Updates `org.springframework.boot:spring-boot-configuration-processor` from 3.1.3 to 3.2.1
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.1.3...v3.2.1)

Updates `org.springframework.boot:spring-boot-dependencies` from 3.1.3 to 3.2.1
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.1.3...v3.2.1)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-configuration-processor
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: org.springframework.boot:spring-boot-dependencies
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

build.gradle

@@ -25,7 +25,7 @@ group = 'de.otto.synapse'
 
 ext {
     awsSdkVersion = "2.20.149"
-    springBootVersion = "3.1.3"
+    springBootVersion = "3.2.1"
     edisonVersion = "3.1.7"
 }