Bump org.openjdk.nashorn:nashorn-core from 15.4 to 15.6

Bumps [org.openjdk.nashorn:nashorn-core](https://github.com/openjdk/nashorn) from 15.4 to 15.6.
- [Changelog](https://github.com/openjdk/nashorn/blob/main/CHANGELOG.md)
- [Commits](openjdk/nashorn@release-15.4...release-15.6)

---
updated-dependencies:
- dependency-name: org.openjdk.nashorn:nashorn-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

common/build.gradle.kts

@@ -1,5 +1,5 @@
 dependencies {
-    compileOnly("org.openjdk.nashorn:nashorn-core:15.4")
+    compileOnly("org.openjdk.nashorn:nashorn-core:15.6")
     compileOnly("com.google.code.gson:gson:2.11.0")
 }