### 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
LineEdit *current_search_box = nullptr;
	if (display_mode == DISPLAY_MODE_TREE_ONLY) {
		current_search_box = tree_search_box;
	} else if (display_mode == DISPLAY_MODE_SPLIT) {
		current_search_box = file_list_search_box;
	}
	if (current_search_box) {
		current_search_box->grab_focus();
		current_search_box->select_all();
	}
}
ScriptCreateDialog *FileSystemDock::get_script_create_dialog() const {
	return make_script_dialog;
}
void FileSystemDock::set_file_list_display_mode(FileListDisplayMode p_mode) {
	if (p_mode == file_list_display_mode) {
		return;
	}
	_toggle_file_display();
}
void FileSystemDock::add_resource_tooltip_plugin(const Ref<EditorResourceTooltipPlugin> &p_plugin) {
	tooltip_plugins.push_back(p_plugin);
}
void FileSystemDock::remove_resource_tooltip_plugin(const Ref<EditorResourceTooltipPlugin> &p_plugin) {
	int index = tooltip_plugins.find(p_plugin);
	ERR_FAIL_COND_MSG(index == -1, "Can't remove plugin that wasn't registered.");
	tooltip_plugins.remove_at(index);
}
Control *FileSystemDock::create_tooltip_for_path(const String &p_path) const {