### 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_
LOG.exception("Error executing scheduled alarm", exc_info=e)
        task = self.scheduler.schedule(
            func=calculate_alarm_state,
            period=schedule_period,
            fixed_rate=True,
            args=[alarm_arn],
            on_error=on_error,
        )
        self.scheduled_alarms[alarm_arn] = task
    def delete_scheduler_for_alarm(self, alarm_arn: str) -> None:
        """
        Deletes the recurring scheduler for an alarm
        :param alarm_arn: the arn of the alarm to be removed
        """
        task = self.scheduled_alarms.pop(alarm_arn, None)
        if task:
            task.cancel()
    def restart_existing_alarms(self) -> None: