Support for Kotlin Multiplatform

[yschimke]

Before this PR

See https://github.com/palantir/gradle-graal/issues/129

Plugins with kotlin("multiplatform") don't have jar or runtimeClasspath.

Gradle don't consider this a bug https://github.com/gradle/gradle/issues/19449, because different project types like jvm, multiplatform, spring-boot should all be supported by plugins such as this.

There are two workarounds I needed to get this working

https://github.com/square/okhttp/blob/master/okcurl/build.gradle.kts#L59

https://github.com/square/okhttp/blob/master/okcurl/build.gradle.kts#L104

After this PR

==COMMIT_MSG== Support Kotlin Multiplatform projects. ==COMMIT_MSG==

Possible downsides?

The approach suggested in https://github.com/gradle/gradle/issues/19449 is to push this onto developers, so it might be a cleaner solution to make these elements configurable.

[palantirtech]

Thanks for your interest in palantir/gradle-graal, @yschimke! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[changelog-app[bot]]

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Type See change types. Select one:

• [ ] Feature
• [ ] Improvement
• [ ] Fix
• [ ] Break
• [ ] Deprecation
• [ ] Manual task
• [ ] Migration

Description Support Kotlin Multiplatform projects.

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