If the solution is indeed to not attach the server dependency to the test configuration, that can be achieved by defining the property on the pw ext like so:
paperweight {
addServerDependencyTo = configurations.named(JavaPlugin.COMPILE_ONLY_CONFIGURATION_NAME).map { setOf(it) }
}
(note that this is a feature of paperweight 2.x)
Originally posted by @lynxplay in MockBukkit/MockBukkit#1154 (comment)