[Bug] Creating `elasticstack_elasticsearch_index` with a mapping results in provider error

[Zawadidone]

Describe the bug
Creating an Elasticsearch index combined with a dynamic index template, results in a provider error since version 0.11.7.

The temporary solution is to revert back to version 0.11.6.

To Reproduce

Steps to reproduce the behavior:

1. TF configuration with elasticstack_elasticsearch_index and elasticstack_elasticsearch_index_template with a dynamic index template (https://www.elastic.co/guide/en/elasticsearch/reference/current/dynamic-templates.html)
2. Execute terraform apply
3. The index was successfully created but the provider returned an inconsistent result.
4. See the error in the output.

╷
 Error: Provider produced inconsistent result after apply
│ 
│ When applying changes to elasticstack_elasticsearch_index.index, provider
│ "provider[\"registry.terraform.io/elastic/elasticstack\"]" produced an unexpected new value: .mappings: was cty.StringVal("{}"), but now
│ cty.StringVal("{\"dynamic_templates\":"[...]").
│ 
│ This is a bug in the provider, which should be reported in the provider's own issue tracker.

Expected behavior

The creation of a Elasticsearch index without an error.

Debug output

I could not find the error in the log. All the API calls to Elasticsearch returned status 200.

Versions (please complete the following information):

• OS: Linux Alpine
• Terraform Version 1.8.1
• Provider version 0.11.7
• Elasticsearch Version 8.15.2