v3.2.2: updated various gradle scripts in prep for 9.0 later

desktop/build.gradle

@@ -1,11 +1,13 @@
 plugins {
-    id 'org.beryx.runtime' version '1.12.7'
+    //TODO currently breaks on Gradle 9+, but is being worked on. Update when I can
+    id 'org.beryx.runtime' version '1.13.1'
 }
 
 [compileJava, compileTestJava]*.options*.encoding = 'UTF-8'
-sourceCompatibility = targetCompatibility = appJavaCompatibility
+java.sourceCompatibility = java.targetCompatibility = appJavaCompatibility
 
 ext.appMainClass = "com.shatteredpixel.shatteredpixeldungeon.desktop.DesktopLauncher"
+application.mainClass = appMainClass
 processResources {
     from new File(project(':core').projectDir, "/src/main/assets")
     from new File(project(':desktop').projectDir,"/src/main/assets")
@@ -13,11 +15,11 @@ processResources {
 
 def osName = System.getProperty('os.name').toLowerCase(Locale.ROOT)
 
-task debug(type: JavaExec) {
+tasks.register('debug', JavaExec) {
     classpath = sourceSets.main.runtimeClasspath
     ignoreExitValue = true
 
-    main = appMainClass
+    mainClass = appMainClass
     systemProperty 'Specification-Title', appName
     systemProperty 'Implementation-Title', appPackageName
     systemProperty 'Specification-Version', appVersionName + "-INDEV"
@@ -28,7 +30,7 @@ task debug(type: JavaExec) {
     }
 }
 
-task release(type: Jar) {
+tasks.register('release', Jar) {
     //FIXME this is now needed as of gradle 7.0, due to our weird sourceSets setup. Should see if there's a better way to do this
     setDuplicatesStrategy(DuplicatesStrategy.EXCLUDE)
     from sourceSets.main.output