Fix gradle deprecation warnings (#326)

orx-jumpflood/build.gradle.kts

@@ -4,7 +4,7 @@ plugins {
 
 val embedShaders = tasks.register<EmbedShadersTask>("embedShaders") {
     inputDir.set(file("$projectDir/src/shaders/glsl"))
-    outputDir.set(file("$buildDir/generated/shaderKotlin"))
+    outputDir.set(layout.buildDirectory.dir("generated/shaderKotlin"))
     defaultPackage.set("org.openrndr.extra.jumpflood")
     defaultVisibility.set("internal")
     namePrefix.set("jf_")