Creating metadata archive crashes if same file referenced more than once

[brunchboy]

Describe the bug
TomRex on Zulip discovered that he could not import his large SSD because it kept crashing on a particular track:

2024-Jun-17 20:30:55.054 MacBook-Pro-2.fritz.box ERROR [beat-link-trigger.track-loader:2672] - Problem Creating Metadata Archive
                                     java.lang.Thread.run                        
       java.util.concurrent.ThreadPoolExecutor$Worker.run                        
        java.util.concurrent.ThreadPoolExecutor.runWorker                        
                      java.util.concurrent.FutureTask.run                        
                                                      ...                        
                      clojure.core/binding-conveyor-fn/fn          core.clj: 2047
beat-link-trigger.track-loader/create-metadata-archive/fn  track_loader.clj: 2670
     org.deepsymmetry.cratedigger.Archivist.createArchive    Archivist.java:  113
                                 java.nio.file.Files.copy                        
         java.nio.file.CopyMoveHelper.copyToForeignTarget                        
java.nio.file.FileAlreadyExistsException: /PIONEER/USBANLZ/P061/0001A42B/ANLZ0000.DAT
    file: "/PIONEER/USBANLZ/P061/0001A42B/ANLZ0000.DAT"

It looks like sometimes track entries share the same analysis file somehow, so we need to cope with this.