### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

When calling 

`cloudWatchClient.EnableAlarmActions(&cloudwatch.EnableAlarmActionsInput{AlarmNames: alarmNames})`

with golang I receive a SerializationError with bytes in the error message saying: 

`<!DOCTYPE HTM |UBLIC "-//W3C//DTD HTML 3.2 Final//EN">.<title>500 Internal Server Error</title>.<h1>Internal Server Error</h1>.<p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.`

I believe this is a bug, since other cloudwatch operations like "DescribeAlarms" work flawlessly with the same client.

### Expected Behavior

I expected the call to go through without any errors

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

Start localstack, create alarms and call cloudwatch "EnableAlarmActions"

### Environment

_No response_

### Anything else?

_No response_
self, context: RequestContext, resource_arn: AmazonResourceName
    ) -> ListTagsForResourceOutput:
        tags = self.tags.list_tags_for_resource(resource_arn)
        return ListTagsForResourceOutput(Tags=tags.get("Tags", []))
    def untag_resource(
        self, context: RequestContext, resource_arn: AmazonResourceName, tag_keys: TagKeyList
    ) -> UntagResourceOutput:
        self.tags.untag_resource(resource_arn, tag_keys)
        return UntagResourceOutput()
    def tag_resource(
        self, context: RequestContext, resource_arn: AmazonResourceName, tags: TagList
    ) -> TagResourceOutput:
        self.tags.tag_resource(resource_arn, tags)
        return TagResourceOutput()
    @handler("PutMetricAlarm", expand=False)
    def put_metric_alarm(
        self,
        context: RequestContext,
        request: PutMetricAlarmInput,
    ) -> None:
        
        if not request.get("TreatMissingData", "missing") in [
            "breaching",
            "notBreaching",
            "ignore",
            "missing",
        ]:
            raise ValidationError(
                f"The value {request['TreatMissingData']} is not supported for TreatMissingData parameter. Supported values are [breaching, notBreaching, ignore, missing]."