enhance: Improve shared issue tracker handling in RepositoryConfigure

Refactor the handling of shared issue trackers by reusing the `Commands.SharedIssueTracker` instance. Enhance the removal logic to check for the existence of the tracker file and delete it if empty.

Author: massimopaganigh

src/ViewModels/RepositoryConfigure.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.IO;
 using System.Threading.Tasks;
 
 using Avalonia.Collections;
@@ -305,10 +306,26 @@ public async Task ChangeIssueTrackerShareModeAsync()
             if (_selectedIssueTrackerRule is not { } rule)
                 return;
 
+            var sharedTracker = new Commands.SharedIssueTracker(_repo.FullPath);
+
             if (rule.IsShared)
-                await new Commands.SharedIssueTracker(_repo.FullPath).AddAsync(rule);
+                await sharedTracker.AddAsync(rule);
             else
-                await new Commands.SharedIssueTracker(_repo.FullPath).RemoveAsync(rule);
+            {
+                await sharedTracker.RemoveAsync(rule);
+
+                if ((await sharedTracker.ReadAllAsync()).Count != 0)
+                    return;
+                
+                var filePath = Path.Combine(_repo.FullPath, ".issuetracker");
+                var content = await File.ReadAllTextAsync(filePath);
+
+                if (!string.IsNullOrEmpty(content))
+                    return;
+                
+                if (File.Exists(filePath))
+                    File.Delete(filePath);
+            }
         }
 
         public void AddNewCustomAction()