Fix eclipse compilation after plugin spi (#76437)
Fix eclipse compilation after plugin spi (#76437)

Painless extensions now compile against it's `spi` subproject. Gradle
and IntelliJ rig the dependencies correctly but Eclipse doesn't seem to
manage it. This temporarily declares the `spi` as a `compileOnly`
dependency when in Eclipse land so Eclipse can see the classes.


GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch,GlenRSmith/elasticsearch