[BUG] Different type received in the input when using mass transit

## Description
We created a INotificationHandler and we tried getting the value of an input. That value was of type dictionary when using mass-transit and of type expando object when not using mass-transit.

## Steps to Reproduce
- Define a new
- Try to access the input
```csharp
public async Task HandleAsync(WorkflowExecuted notification, CancellationToken cancellationToken)
{
var workflowInput = notification.WorkflowExecutionContext.Input;
workflowInput.TryGetValue("Headers", out var headersInput)

```

3. **Attachments**:
No attachments

4. **Reproduction Rate**: Indicate how often the bug occurs when following these steps (e.g., "every time", "intermittently: about 50% of the time").
Every time.

5. **Video/Screenshots**: Sometimes, complex behaviors are better shown than described. If you think a video or screenshots would help clarify the issue, please include them.
No screenshots or video.

6. **Additional Configuration**:
Mass transit enabled/disabled.

## Expected Behavior
Received the same type no matter which provider you use.

## Actual Behavior
Different type received when inspecting the headersInput depending if mass-transit in enabled or not.

## Screenshots
No screenshot.

## Environment
Elsa version 3.1.0-preview.1209

## Log Output
No log.

## Troubleshooting Attempts
No attempt.

## Additional Context
No additional data.

## Related Issues
No related issue.