Clean up old Mac stuff

[Stereo]

Follow-up from #20146

The remaining parts of the old macOS appbundler infrastructure can be dropped.

• build.xml mac and distmac targets
• xmltask dependency
• native/macosx/JOSM.app
• Server-side parts (?)
• Anything else?

[simon04]

@Stereo, can you provide a patch for the remaining items? Thank you!

[Don-vip]

It seems the mac target is broken and it makes no sense trying to fix it:
https://josm.openstreetmap.de/jenkins/job/JOSM/jdk=JDK8/7352/console

mac:
[bundleapp] Creating app bundle: JOSM
  [xmltask] [Fatal Error] PropertyList-1.0.dtd:1:2: The markup declarations contained or pointed to by the document type declaration must be well-formed.
  [xmltask] org.xml.sax.SAXParseExceptionpublicId: -//Apple//DTD PLIST 1.0//EN; systemId: http://www.apple.com/DTDs/PropertyList-1.0.dtd; lineNumber: 1; columnNumber: 2; The markup declarations contained or pointed to by the document type declaration must be well-formed.
  [xmltask] 	at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:257)
  [xmltask] 	at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
  [xmltask] 	at com.oopsconsultancy.xmltask.ant.XmlTask.documentFromStream(XmlTask.java:353)
  [xmltask] 	at com.oopsconsultancy.xmltask.ant.XmlTask.documentFromFile(XmlTask.java:397)
  [xmltask] 	at com.oopsconsultancy.xmltask.ant.XmlTask.access$0(XmlTask.java:396)
  [xmltask] 	at com.oopsconsultancy.xmltask.ant.XmlTask$InputFile.getDocument(XmlTask.java:213)
  [xmltask] 	at com.oopsconsultancy.xmltask.ant.XmlTask.execute(XmlTask.java:648)
  [xmltask] 	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
  [xmltask] 	at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
  [xmltask] 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  [xmltask] 	at java.lang.reflect.Method.invoke(Method.java:498)
  [xmltask] 	at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:99)
  [xmltask] 	at org.apache.tools.ant.Task.perform(Task.java:350)
  [xmltask] 	at org.apache.tools.ant.Target.execute(Target.java:449)
  [xmltask] 	at org.apache.tools.ant.Target.performTasks(Target.java:470)
  [xmltask] 	at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1401)
  [xmltask] 	at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:36)
  [xmltask] 	at org.apache.tools.ant.Project.executeTargets(Project.java:1264)
  [xmltask] 	at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:437)
  [xmltask] 	at org.apache.tools.ant.taskdefs.CallTarget.execute(CallTarget.java:106)
  [xmltask] 	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
  [xmltask] 	at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
  [xmltask] 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  [xmltask] 	at java.lang.reflect.Method.invoke(Method.java:498)
  [xmltask] 	at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:99)
  [xmltask] 	at org.apache.tools.ant.Task.perform(Task.java:350)
  [xmltask] 	at org.apache.tools.ant.Target.execute(Target.java:449)
  [xmltask] 	at org.apache.tools.ant.Target.performTasks(Target.java:470)
  [xmltask] 	at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1401)
  [xmltask] 	at org.apache.tools.ant.Project.executeTarget(Project.java:1374)
  [xmltask] 	at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
  [xmltask] 	at org.apache.tools.ant.Project.executeTargets(Project.java:1264)
  [xmltask] 	at org.apache.tools.ant.Main.runBuild(Main.java:827)
  [xmltask] 	at org.apache.tools.ant.Main.startAnt(Main.java:223)
  [xmltask] 	at org.apache.tools.ant.launch.Launcher.run(Launcher.java:284)
  [xmltask] 	at org.apache.tools.ant.launch.Launcher.main(Launcher.java:101)

BUILD FAILED
/var/lib/jenkins/jobs/JOSM/workspace/jdk/JDK8/build.xml:226: The following error occurred while executing this line:
/var/lib/jenkins/jobs/JOSM/workspace/jdk/JDK8/build.xml:212: The markup declarations contained or pointed to by the document type declaration must be well-formed.

[Don-vip]

In 17884/josm:

fix #20500 - drop old macOS appbundle generation code