build.sbt: method libraryJar in trait ScalaInstance is deprecated

[EwoutH]

I noticed a depreciation warning for build.sbt during a CI run.

[info] loading project definition from /home/runner/work/NetLogo/NetLogo/extensions/matrix/project
/home/runner/work/NetLogo/NetLogo/extensions/matrix/build.sbt:45: warning: method libraryJar in trait ScalaInstance is deprecated: see corresponding Javadoc for more information.
  val classpath = (allDependencies :+ scalaInstance.value.libraryJar).map(_.getPath).mkString(":")
                                                          ^