Add the runtime-dir option to pluginVerifier

[opticyclic]

Problem
I get the following error when running the runPluginVerifier task imported in my own plugin project

Exception in thread "main" java.lang.IllegalArgumentException: JAVA_HOME is not specified
    at com.jetbrains.pluginverifier.options.OptionsParser.getJdkPath(OptionsParser.kt:76)
    at com.jetbrains.pluginverifier.options.OptionsParser.createIdeDescriptor(OptionsParser.kt:66)
    at com.jetbrains.pluginverifier.tasks.checkPlugin.CheckPluginParamsBuilder.build(CheckPluginParamsBuilder.kt:38)
    at com.jetbrains.pluginverifier.tasks.checkPlugin.CheckPluginParamsBuilder.build(CheckPluginParamsBuilder.kt:23)
    at com.jetbrains.pluginverifier.PluginVerifierMain.main(PluginVerifierMain.kt:124)

This is due to a combination of how IDEA is started without the JAVA_HOME variable and how the PluginVerifier doesn't do a full search of the environment for a JDK.

https://github.com/JetBrains/intellij-plugin-verifier/issues/35

Suggested solution
Could you add the option to pass the -runtime-dir option to the task
https://github.com/FWDekker/intellij-randomness/blob/master/gradle/scripts/verifier.gradle#L151-L162

Alternative solutions
I could make sure that JAVA_HOME was set everywhere I wanted to use this.

Additional context
I also would like the ability to specify a different runtime than my current one so I can test different variations in a build server.

I am also aware that this is mainly for your project and not primarily designed for use by other people via an import.

[FWDekker]

You're right that it's preferable if you don't import this script from a URL since I have plans to eventually incorporate the functionality into the gradle-intellij-plugin, after which I'll remove the script from this repository. Since there's probably a few repositories depending on the script I'll try to do a deprecation phase, but just be careful.