### 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
ED_SHORTCUT("filesystem_dock/duplicate", TTR("Duplicate..."), KeyModifierMask::CMD_OR_CTRL | Key::D);
	ED_SHORTCUT("filesystem_dock/delete", TTR("Delete"), Key::KEY_DELETE);
	ED_SHORTCUT("filesystem_dock/rename", TTR("Rename..."), Key::F2);
	ED_SHORTCUT_OVERRIDE("filesystem_dock/rename", "macos", Key::ENTER);
#if !defined(ANDROID_ENABLED) && !defined(WEB_ENABLED)
	
	ED_SHORTCUT("filesystem_dock/show_in_explorer", TTR("Open in File Manager"));
	ED_SHORTCUT("filesystem_dock/open_in_external_program", TTR("Open in External Program"));
#endif
	VBoxContainer *top_vbc = memnew(VBoxContainer);
	add_child(top_vbc);
	HBoxContainer *toolbar_hbc = memnew(HBoxContainer);
	toolbar_hbc->add_theme_constant_override("separation", 0);
	top_vbc->add_child(toolbar_hbc);
	button_hist_prev = memnew(Button);
	button_hist_prev->set_flat(true);
	button_hist_prev->set_disabled(true);
	button_hist_prev->set_focus_mode(FOCUS_NONE);
	button_hist_prev->set_tooltip_text(TTR("Go to previous selected folder/file."));
	toolbar_hbc->add_child(button_hist_prev);
	button_hist_next = memnew(Button);
	button_hist_next->set_flat(true);
	button_hist_next->set_disabled(true);
	button_hist_next->set_focus_mode(FOCUS_NONE);
	button_hist_next->set_tooltip_text(TTR("Go to next selected folder/file."));
	toolbar_hbc->add_child(button_hist_next);
	current_path_line_edit = memnew(LineEdit);
	current_path_line_edit->set_structured_text_bidi_override(TextServer::STRUCTURED_TEXT_FILE);
	current_path_line_edit->set_h_size_flags(SIZE_EXPAND_FILL);
	_set_current_path_line_edit_text(current_path);