### Godot version

4.0 Beta 11

### System information

Windows 10 version 22H2, GeForce Game Ready Driver Version 528.02, GTX 1070

### Issue description

Since Beta 11 this error is given whenever a project is run in the forward+ renderer with OpenXR enabled. This error is not present with Beta 10 and previous versions.
![image](https://user-images.githubusercontent.com/38119387/212044209-1179b908-f010-47a1-ae53-bc2faadc30de.png)

I've tested with projects created in previous versions as well as the current version (Beta 11)

### Steps to reproduce

Create project, enable OpenXR in project settings, and run.

### Minimal reproduction project

N/A
if (supported_extensions != nullptr) {
		
		return true;
	}
	
	XrResult result = xrEnumerateInstanceExtensionProperties(nullptr, 0, &num_supported_extensions, nullptr);
	ERR_FAIL_COND_V_MSG(XR_FAILED(result), false, "OpenXR: Failed to enumerate number of extension properties");
	supported_extensions = (XrExtensionProperties *)memalloc(sizeof(XrExtensionProperties) * num_supported_extensions);
	ERR_FAIL_NULL_V(supported_extensions, false);
	
	for (uint32_t i = 0; i < num_supported_extensions; i++) {
		supported_extensions[i].type = XR_TYPE_EXTENSION_PROPERTIES;
		supported_extensions[i].next = nullptr;
	}
	result = xrEnumerateInstanceExtensionProperties(nullptr, num_supported_extensions, &num_supported_extensions, supported_extensions);
	ERR_FAIL_COND_V_MSG(XR_FAILED(result), false, "OpenXR: Failed to enumerate extension properties");
	for (uint32_t i = 0; i < num_supported_extensions; i++) {
		print_verbose(String("OpenXR: Found OpenXR extension ") + supported_extensions[i].extensionName);
	}
	return true;
}
bool OpenXRAPI::is_extension_supported(const String &p_extension) const {