Bump plugin.spring from 1.9.20 to 2.0.20

Bumps [plugin.spring](https://github.com/JetBrains/kotlin) from 1.9.20 to 2.0.20.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.20...v2.0.20)

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

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

Author: dependabot[bot]

build.gradle.kts

@@ -1,6 +1,6 @@
 plugins {
   id("uk.gov.justice.hmpps.gradle-spring-boot") version "6.0.4"
-  kotlin("plugin.spring") version "1.9.20"
+  kotlin("plugin.spring") version "2.0.20"
 }
 
 configurations {