### 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
String ssh_path = EditorSettings::get_singleton()->get("export/ssh/ssh");
	if (ssh_path.is_empty()) {
		ssh_path = "ssh";
	}
	List<String> args;
	args.push_back("-p");
	args.push_back(p_port);
	args.push_back("-q");
	args.push_back("-o");
	args.push_back("LogLevel=error");
	args.push_back("-o");
	args.push_back("BatchMode=yes");
	args.push_back("-o");
	args.push_back("StrictHostKeyChecking=no");
	for (const String &E : p_ssh_args) {