Remove support for Kotlin scripting engine

[sdeleuze]

Kotlin team has expressed the intent to drop Kotlin scripting engine support via JSR 223 (javax.script.ScriptEngine) and ExecuteKotlinScriptMojo APIs in Kotlin 2.x, which is used in Spring View support. Spring Framework 7 should remove related test, support and update the documentation accordingly.

[sdeleuze]

Closing as duplicated of #34030 since we don't really remove support from Spring, just we anticipate Kotlin upcoming changes by removing related tests and documentation.