### 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_
alarm_name = "a-%s" % short_uid()
        response = cloudwatch_client.put_metric_alarm(
            AlarmName=alarm_name,
            EvaluationPeriods=1,
            ComparisonOperator="GreaterThanThreshold",
        )
        assert 200 == response["ResponseMetadata"]["HTTPStatusCode"]
        alarm_arn = aws_stack.cloudwatch_alarm_arn(alarm_name)
        tags = [{"Key": "tag1", "Value": "foo"}, {"Key": "tag2", "Value": "bar"}]
        response = cloudwatch_client.tag_resource(ResourceARN=alarm_arn, Tags=tags)
        assert 200 == response["ResponseMetadata"]["HTTPStatusCode"]
        response = cloudwatch_client.list_tags_for_resource(ResourceARN=alarm_arn)
        assert 200 == response["ResponseMetadata"]["HTTPStatusCode"]
        assert tags, response["Tags"]
        response = cloudwatch_client.untag_resource(ResourceARN=alarm_arn, TagKeys=["tag1"])
        assert 200 == response["ResponseMetadata"]["HTTPStatusCode"]
        response = cloudwatch_client.list_tags_for_resource(ResourceARN=alarm_arn)
        assert 200 == response["ResponseMetadata"]["HTTPStatusCode"]
        assert [{"Key": "tag2", "Value": "bar"}] == response["Tags"]
        
        cloudwatch_client.delete_alarms(AlarmNames=[alarm_name])
    def test_list_metrics_uniqueness(self, cloudwatch_client):