Kubernetes: Recaptcha secret is required

Our kubernetes deployment requires Recaptcha to be enabled.
If you don't set the secret in the environment, the deployment works, but the api does not allow you to register.
```
{"message":"Uncaught PHP Exception RuntimeException: \"No secret provided\" at /srv/api/vendor/google/recaptcha/src/ReCaptcha/ReCaptcha.php line 142","context":{"exception":{"class":"RuntimeException","message":"No secret provided","code":0,"file":"/srv/api/vendor/google/recaptcha/src/ReCaptcha/ReCaptcha.php:142"}},"level":500,"level_name":"CRITICAL","channel":"request","datetime":"2023-02-27T13:56:41.784593+00:00","extra":{}}
```

Either:
- Allow to use ecamp without recaptcha Secret
- Fail the helm chart deployment if the secret is not set