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

Bumps [org.springframework.boot:spring-boot-gradle-plugin](https://github.com/spring-projects/spring-boot) from 2.7.18 to 3.3.1.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.7.18...v3.3.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -2,7 +2,7 @@ import org.springframework.boot.gradle.tasks.run.BootRun
 
 buildscript {
     ext {
-        springBootVersion = '2.7.18'
+        springBootVersion = '3.3.1'
     }
     repositories {
         mavenLocal()