### Godot version

v4.1.rc2.official [46424488e]

### System information

Godot v4.1.rc2 - Linux Mint 20 (Ulyana) - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2060 SUPER (nvidia; 515.105.01) - Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz (8 Threads)

### Issue description

Dragging and dropping a file to a new position inside its current folder, or onto the icon for its current folder - when that folder is the project root folder :res// - will be treated as though you were dropping a different file with the same name.

Expectation: for nothing to happen.

Also tried it in 4.0.3 and 4.1-dev3, where it behaves as expected.

https://github.com/godotengine/godot/assets/64640811/90de1120-dd92-41b8-b202-db77c343103a

### Steps to reproduce

1. New or existing project.
2. Click and drag a file in :res// in FileSystem dock.
3. Drop the file back into :res//.
4. Be prompted to overwrite or rename.

### Minimal reproduction project

N/A
remove_dialog->connect("folder_removed", callable_mp(this, &FileSystemDock::_folder_removed));
	add_child(remove_dialog);
	move_dialog = memnew(EditorDirDialog);
	add_child(move_dialog);
	move_dialog->connect("dir_selected", callable_mp(this, &FileSystemDock::_move_dialog_confirm));
	overwrite_dialog = memnew(ConfirmationDialog);
	add_child(overwrite_dialog);
	overwrite_dialog->set_ok_button_text(TTR("Overwrite"));
	overwrite_dialog->add_button(TTR("Keep Both"), true)->connect("pressed", callable_mp(this, &FileSystemDock::_overwrite_dialog_action).bind(false));
	overwrite_dialog->connect("confirmed", callable_mp(this, &FileSystemDock::_overwrite_dialog_action).bind(true));
	VBoxContainer *overwrite_dialog_vb = memnew(VBoxContainer);
	overwrite_dialog->add_child(overwrite_dialog_vb);
	overwrite_dialog_header = memnew(Label);
	overwrite_dialog_vb->add_child(overwrite_dialog_header);
	overwrite_dialog_scroll = memnew(ScrollContainer);
	overwrite_dialog_vb->add_child(overwrite_dialog_scroll);
	overwrite_dialog_scroll->set_custom_minimum_size(Vector2(400, 600) * EDSCALE);
	overwrite_dialog_file_list = memnew(Label);
	overwrite_dialog_scroll->add_child(overwrite_dialog_file_list);
	overwrite_dialog_footer = memnew(Label);
	overwrite_dialog_vb->add_child(overwrite_dialog_footer);
	duplicate_dialog = memnew(ConfirmationDialog);
	VBoxContainer *duplicate_dialog_vb = memnew(VBoxContainer);
	duplicate_dialog->add_child(duplicate_dialog_vb);
	duplicate_dialog_text = memnew(LineEdit);
	duplicate_dialog_vb->add_margin_child(TTR("Name:"), duplicate_dialog_text);
	duplicate_dialog->set_ok_button_text(TTR("Duplicate"));
	add_child(duplicate_dialog);
	duplicate_dialog->register_text_enter(duplicate_dialog_text);
	duplicate_dialog->connect("confirmed", callable_mp(this, &FileSystemDock::_duplicate_operation_confirm));