Bump org.springframework.boot:spring-boot-gradle-plugin

Bumps [org.springframework.boot:spring-boot-gradle-plugin](https://github.com/spring-projects/spring-boot) from 3.1.1 to 3.1.3.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.1.1...v3.1.3)

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

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

server/build.gradle

@@ -2,7 +2,7 @@ buildscript {
     ext {
         // https://github.com/spring-projects/spring-boot/wiki#release-notes
         // https://github.com/spring-projects/spring-boot/releases
-        springBootVersion = '3.1.1'
+        springBootVersion = '3.1.3'
     }
     repositories {
         mavenCentral()