Resolve type mismatch error in build.gradle.kts scripts

[RenFraser]

This PR shows a TypeError when the language server parses the server/build.gradle.kts script. @themkat has commented the following:

a general issue with our Kotlin DSL code in Compiler.kt

We should investigate and resolve the cause.

See attached screenshot for example:

[themkat]

This issue might or might not be related:

The lambda-related inferred type error is similar, but my image also contains a "not found" error for CreateStartScripts. Let me know if people are not experiencing this issue 🙂 (this is off course by using the language server on itself! IntelliJ will probably not report any errors here. For that reason we can probably look into parts of the IntelliJ codebase for inspiration)