### 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 export_path = _export_customize(path, customize_resources_plugins, customize_scenes_plugins, export_cache, export_base_path, false);
			if (export_path != path) {
				
				
				Ref<ConfigFile> config;
				config.instantiate();
				err = config->load(path + ".import");
				if (err != OK) {
					ERR_PRINT("Could not parse: '" + path + "', not exported.");
					continue;
				}
				config->set_value("remap", "type", ResourceLoader::get_resource_type(export_path));
				
				List<String> keys;
				config->get_section_keys("remap", &keys);
				for (const String &K : keys) {
					if (E.begins_with("path")) {
						config->erase_section_key("remap", K);
					}
				}
				
				config->set_value("remap", "path", export_path);
				
				config->erase_section("deps");
				config->erase_section("params");
				String import_text = config->encode_to_text();
				CharString cs = import_text.utf8();
				Vector<uint8_t> sarr;
				sarr.resize(cs.size());
				memcpy(sarr.ptrw(), cs.ptr(), sarr.size());