### Godot version

4.1.dev (dc625bcbfc5b587ba8867481ee7a1f6a567c25d0)

### System information

Mageia 9, Linux

### Issue description

When importing a project in current `master`, the following error is raised for each asset that gets imported:
```
Attempting to parent and popup a dialog that already has a parent.
```

It seems to be raised once per asset, caused by the progress dialog.

CC @bruvzg

### Steps to reproduce

- Import a new project in Godot that contains importable assets, e.g. https://github.com/RPicster/godot4-demo-desert-light

### Minimal reproduction project

See above.
parent = (slash_idx >= 0 && parent.length() > 1) ? parent.substr(slash_idx + 1) : parent;
					r_filenames.write[set_idx] = parent + r_filenames[set_idx];
				}
			}
			
			bool can_proceed = false;
			RBSet<int>::Element *E = iset.front();
			while (E) {
				String scene_name = r_filenames[E->get()];
				bool duplicate_found = false;
				for (const int &F : iset) {
					if (E->get() == F) {
						continue;
					}
					String other_scene_name = r_filenames[F];
					if (other_scene_name == scene_name) {
						duplicate_found = true;
						break;
					}
				}
				RBSet<int>::Element *to_erase = duplicate_found ? nullptr : E;
				
				
				
				
				
				String path = p_full_paths[E->get()];
				
				scene_name = scene_name.get_basename();
				if (path.begins_with("res:")) {