### 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
#include "editor_export_platform.h"
#include "core/config/project_settings.h"
#include "core/crypto/crypto_core.h"
#include "core/extension/gdextension.h"
#include "core/io/file_access_encrypted.h"
#include "core/io/file_access_pack.h" 
#include "core/io/zip_io.h"
#include "core/version.h"
#include "editor/editor_file_system.h"
#include "editor/editor_node.h"
#include "editor/editor_paths.h"
#include "editor/editor_scale.h"
#include "editor/editor_settings.h"
#include "editor/plugins/script_editor_plugin.h"
#include "editor_export_plugin.h"
#include "scene/resources/packed_scene.h"
static int _get_pad(int p_alignment, int p_n) {