### 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_
target,
    self,
    name,
    namespace,
    metric_name,
    metric_data_queries,
    comparison_operator,
    evaluation_periods,
    datapoints_to_alarm,
    period,
    threshold,
    statistic,
    extended_statistic,
    description,
    dimensions,
    alarm_actions,
    ok_actions,
    insufficient_data_actions,
    unit,
    actions_enabled,
    treat_missing_data,
    evaluate_low_sample_count_percentile,
    threshold_metric_id,
    rule=None,
    tags=None,