### 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
String main_scene = GLOBAL_GET("application/run/main_scene");
	for (FileInfo &E : file_list) {
		FileInfo *finfo = &(E);
		String fname = finfo->name;
		String fpath = finfo->path;
		String ftype = finfo->type;
		Ref<Texture2D> type_icon;
		Ref<Texture2D> big_icon;
		String tooltip = fpath;
		
		if (!finfo->import_broken) {
			type_icon = (has_theme_icon(ftype, SNAME("EditorIcons"))) ? get_theme_icon(ftype, SNAME("EditorIcons")) : get_theme_icon(SNAME("Object"), SNAME("EditorIcons"));
			big_icon = file_thumbnail;
		} else {
			type_icon = get_theme_icon(SNAME("ImportFail"), SNAME("EditorIcons"));
			big_icon = file_thumbnail_broken;
			tooltip += "\n" + TTR("Status: Import of file failed. Please fix file and reimport manually.");
		}
		
		int item_index;
		if (use_thumbnails) {
			files->add_item(fname, big_icon, true);
			item_index = files->get_item_count() - 1;
			files->set_item_metadata(item_index, fpath);
			files->set_item_tag_icon(item_index, type_icon);
		} else {
			files->add_item(fname, type_icon, true);
			item_index = files->get_item_count() - 1;
			files->set_item_metadata(item_index, fpath);