Update of "Datadog::Dashboards::Dashboard" resource fails

[rickard-andersson-wcar]

Describe the bug
We have a CloudFormation stack including one Datadog::Dashboards::Dashboard resource. When we first deploy the stack, the dashboard is created successfully. However, if we deploy the same stack again (even without any changes), the Datadog::Dashboards::Dashboard resource fails to update with error message: 'dict' object has no attribute '_composed_schemas'.

The resource we're trying to update:

OurDashboardResource:
    Type: Datadog::Dashboards::Dashboard
    Properties:
      DashboardDefinition: !Sub |
        {
          "title": "Title of Dashboard",
          "description": "",
          "widgets": [
            {
              "id": 12345,
              "definition": {
                ...definition of widget
              }
            }
          ],
          "template_variables": [],
          "layout_type": "ordered",
          "is_read_only": false,
          "notify_list": [],
          "id": "some-id"
        }
      DatadogCredentials:
        ApiKey: ##API-KEY##
        ApplicationKey: ##APPLICATION-KEY##
        ApiURL: https://api.datadoghq.eu

To Reproduce
Steps to reproduce the behavior:

1. Export an existing dashboard as json and include it as DashboardDefinition of a Datadog::Dashboards::Dashboard resource (similar to above code example)
2. Deploy the CloudFormation stack including the Datadog::Dashboards::Dashboard resource
3. Note that the resource was created successfully
4. Deploy the CloudFormation stack including the Datadog::Dashboards::Dashboard resource again
5. Note that the dashboard resource (and stack) fails to update due to: 'dict' object has no attribute '_composed_schemas'.

Logs
'dict' object has no attribute '_composed_schemas'

Expected behavior
That the resource (and stack) updates successfully.

Environment and Versions (please complete the following information):
1.0.0

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[iwt-dennyschaefer]

With the current released version (1.0.0), the above-mentioned behavior is still present!.