Fix OCI prune cleanup of broken tag symlinks

Author: mikemikimike

Sources/tart/Commands/Prune.swift

@@ -72,6 +72,12 @@ struct Prune: AsyncParsableCommand {
     if let spaceBudget = spaceBudget {
       try Prune.pruneSpaceBudget(prunableStorages: prunableStorages, spaceBudgetBytes: UInt64(spaceBudget) * 1024 * 1024 * 1024)
     }
+
+    // Pruning digest-addressed OCI images can leave their tag symlinks broken.
+    // Run garbage collection after deletion so it can remove those links.
+    if entries == "caches" && (olderThan != nil || spaceBudget != nil) {
+      try VMStorageOCI().gc()
+    }
   }
 
   static func pruneOlderThan(prunableStorages: [PrunableStorage], olderThanDate: Date) throws {