Eclipse doesn't automatically attach sources due to JAR layout

[the-former-programmer]

The current java sources layout looks like this:
root
-META-INF
-main
--com
---openai

But the layout needs to look like
root
-META-INF
-com
--openai

This is to support the automatic attachment of sources within IDEs like Eclipse.

[TomerAberbach]

We use vanniktech/gradle-maven-publish-plugin, and apparently this has come up before: vanniktech/gradle-maven-publish-plugin#674

It appears that the default kotlinSourcesJar task does this, while plain sourcesJar doesn't.