### Godot version

any version after 74458b6

### System information

Linux x64, but likely irrelevant

### Issue description

OpenXR action maps are not properly exported in recent builds of Godot 4: the `.res` file is small and does no longer seem to contain anything of use. In-game, no actions are passed on to OpenXR (obviously).

I bisected the issue down to https://github.com/godotengine/godot/commit/74458b6e9bed0f28db3374c7406eacbcf4b09b9d, which was merged in #70377.

### Steps to reproduce

1. Delete any previous export files (`.godot/exported/*/*.pkg`)
2. Perform an export (I did one for Android, but it likely works with anything)
3. Observe OpenXR actions not working in the export (error spam 'sync_action_sets: Condition "active_sets.size() == 0"'), and the exported action map file being very small (`.godot/exported/*/*.pkg`, from a few tens of kilobytes down to 296 bytes)

### Minimal reproduction project

Any OpenXR project can be used, such as https://github.com/BastiaanOlij/godot4_openxr_demo
int rest = p_n % p_alignment;
	int pad = 0;
	if (rest > 0) {
		pad = p_alignment - rest;
	};
	return pad;
}
#define PCK_PADDING 16
bool EditorExportPlatform::fill_log_messages(RichTextLabel *p_log, Error p_err) {
	bool has_messages = false;
	int msg_count = get_message_count();
	p_log->add_text(TTR("Project export for platform:") + " ");
	p_log->add_image(get_logo(), 16 * EDSCALE, 16 * EDSCALE, Color(1.0, 1.0, 1.0), INLINE_ALIGNMENT_CENTER);
	p_log->add_text(" ");
	p_log->add_text(get_name());
	p_log->add_text(" - ");
	if (p_err == OK) {
		if (get_worst_message_type() >= EditorExportPlatform::EXPORT_MESSAGE_WARNING) {
			p_log->add_image(EditorNode::get_singleton()->get_gui_base()->get_theme_icon(SNAME("StatusWarning"), SNAME("EditorIcons")), 16 * EDSCALE, 16 * EDSCALE, Color(1.0, 1.0, 1.0), INLINE_ALIGNMENT_CENTER);
			p_log->add_text(" ");
			p_log->add_text(TTR("Completed with warnings."));
			has_messages = true;
		} else {
			p_log->add_image(EditorNode::get_singleton()->get_gui_base()->get_theme_icon(SNAME("StatusSuccess"), SNAME("EditorIcons")), 16 * EDSCALE, 16 * EDSCALE, Color(1.0, 1.0, 1.0), INLINE_ALIGNMENT_CENTER);
			p_log->add_text(" ");
			p_log->add_text(TTR("Completed successfully."));
			if (msg_count > 0) {
				has_messages = true;
			}