remove file from in-memory cache on tab close

src/SharpIDE.Application/Features/FilePersistence/IdeOpenTabsFileManager.cs

@@ -70,6 +70,11 @@ public class IdeOpenTabsFileManager
 			await SaveFileAsync(file);
 		}
 	}
+
+	public void CloseFile(SharpIdeFile file)
+	{
+		_openFiles.TryRemove(file, out _);
+	}
 }
 
 #pragma warning restore VSTHRD011

src/SharpIDE.Godot/Features/CodeEditor/SharpIdeCodeEdit.cs

@@ -126,6 +126,7 @@ public partial class SharpIdeCodeEdit : CodeEdit
 	{
 		_currentFile?.FileContentsChangedExternally.Unsubscribe(OnFileChangedExternally);
 		GlobalEvents.Instance.SolutionAltered.Unsubscribe(OnSolutionAltered);
+		_openTabsFileManager.CloseFile(_currentFile!);
 	}
 
 	private void OnBreakpointToggled(long line)