PHPStan Error in google/cloud-recaptcha-enterprise

Since the package is deprecated, I was unsure which issue type would be appropriate, but I am submitting this as a **Bug Report** because a PHPStan error occurs.

#### Environment details

- OS: Debian GNU/Linux 12 (bookworm)
- PHP version: 8.3.22
- Package name and version: `google/cloud-recaptcha-enterprise:2.1.1`, `google/protobuf:4.31.1`
#### Steps to reproduce

1. Create an instance of `RecaptchaEnterpriseServiceClient`.
2. Create a `CreateAssessmentRequest` object.
3. Send the request using the client.
4. Access the `RiskAnalysis` of the returned `Assessment` and call `getReasons()`.
5. Attempt to call `getIterator()` on the result of `getReasons()`.
6. A PHPStan error occurs.
#### Code example

```php
use Google\Cloud\RecaptchaEnterprise\V1\Assessment;
use Google\Cloud\RecaptchaEnterprise\V1\Client\RecaptchaEnterpriseServiceClient;
use Google\Cloud\RecaptchaEnterprise\V1\CreateAssessmentRequest;

// Credentials are actually passed when creating the client
$client = new RecaptchaEnterpriseServiceClient();

// Omitted: building the Assessment instance
$assessment = new Assessment();
$assessmentRequest = CreateAssessmentRequest::build($parent, $assessment);

$createdAssessment = $client->createAssessment($assessmentRequest);
$createdAssessment->getRiskAnalysis()?->getReasons()->getIterator(); // Call to an undefined method Google\Protobuf\Internal\RepeatedField::getIterator().
```

I’ve been following the protobuf updates and it appears this issue may be due to changes introduced here:

[https://github.com/protocolbuffers/protobuf-php/commit/9a6ad10d77de8a6d3320f10bd097bed8d6021ac1#diff-f4adb7d6333d82634864e3424d178a65e8c6e413c257198fd8371622e1e0b303](https://github.com/protocolbuffers/protobuf-php/commit/9a6ad10d77de8a6d3320f10bd097bed8d6021ac1#diff-f4adb7d6333d82634864e3424d178a65e8c6e413c257198fd8371622e1e0b303)

I understand that this package is deprecated and things still function for now, but I wanted to report this for future compatibility and also because this causes a PHPStan error. I’d appreciate it if you could consider addressing it.