### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When a scheduled rules runs, an empty event is generated and sent to targets.

### Expected Behavior

An event like this sample should be sent.
```json
{
  "version": "0",
  "id": "89d1a02d-5ec7-412e-82f5-13505f849b41",
  "detail-type": "Scheduled Event",
  "source": "aws.events",
  "account": "123456789012",
  "time": "2016-12-30T18:44:49Z",
  "region": "us-east-1",
  "resources": ["arn:aws:events:us-east-1:123456789012:rule/SampleRule"],
  "detail": {}
}
```

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    docker-compose up

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

    awslocal events put-rule --name scheduled_rule --schedule-expression "rate(1 minutes)"
    awslocal events put-targets --rule scheduled_rule --targets "Id"="1","Arn"="arn:aws:logs:us-east-1:000000000000:log-group:/aws/events/echo"
    awslocal--endpoint-url=http://localhost:4566 logs tail "/aws/events/echo"

### Environment

```markdown
- OS: macOS Monterey
- LocalStack: 0.13.3
```


### Anything else?
I think [this](https://github.com/localstack/localstack/blob/1567f25a8f672f4dec23cb7cb1aadb5a744366f8/localstack/services/events/events_listener.py#L92) means an non-empty event is sent only when an input is `Constant (JSON text)`.
![image](https://user-images.githubusercontent.com/4127030/151643813-a4d1e113-dba3-41ad-8400-da57e4f674a1.png)

if (
                        isinstance(event_value, list)
                        and get_two_lists_intersection(value, event_value) == []
                    ):
                        return False
                    if (
                        not isinstance(event_value, list)
                        and isinstance(event_value, (str, int))
                        and event_value not in value
                    ):
                        return False
            
            elif isinstance(value, (str, dict)):
                try:
                    value = json.loads(value) if isinstance(value, str) else value
                    if isinstance(value, dict) and not filter_event(value, event_value):
                        return False
                except json.decoder.JSONDecodeError:
                    return False
        return True
    rule_information = self.events_backend.describe_rule(rule_name, event_bus_arn(event_bus_name))
    if not rule_information:
        LOG.info('Unable to find rule "%s" in backend: %s', rule_name, rule_information)
        return False
    if rule_information.event_pattern._pattern:
        event_pattern = rule_information.event_pattern._pattern
        if not filter_event(event_pattern, event):
            return False
    return True
def filter_event_with_target_input_path(target: Dict, event: Dict) -> Dict: