Gradle build is not excluding jalview.appletgui/java.applet classes

The ant build (pre 2.11.0.0/2019) had exclusions for most/all the jalview.appletgui classes, meaning that java.applet.* classes are not needed for a Java desktop build of Jalview.
java.applet is still needed for a jalviewjs transpile.

In Java 17 the java.applet package is completely removed, so a compilation that imports any of these packages fails. With exclusions did could be made to work.

Note: for a jalviewjs/jalview.bin.JalviewLite transpilation the java.applet.Applet class is required (or rather the JSObject.getWindow(Applet) method is required). The JSObject class remains in Java 17 but the getWindow(Applet) method has been removed along with the java.applet package.
https://github.com/adoptium/jdk17u/blob/master/src/jdk.jsobject/share/classes/netscape/javascript/JSObject.java