### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

If the Lambda returns an error, the message is put into DLQ straightaway after first try **although** the configurations says "try 3 times".

### Expected Behavior

If the Lambda returns an error, the message should be put into DLQ after what `RedrivePolicy.maxReceiveCount` says which is 3 in this case. For instance, try processing the message 3 times, if still no success, put it into DLQ.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

```yaml
version: "3.8"

services:
  localstack:
    image: "localstack/localstack"
    container_name: "localstack"
    ports:
      - "4566-4599:4566-4599"
    environment:
      - DEBUG=1
      - DEFAULT_REGION=eu-west-1
      - SERVICES=lambda,events,sqs
      - DATA_DIR=/tmp/localstack/data
      - DOCKER_HOST=unix:///var/run/docker.sock
      - LAMBDA_EXECUTOR=docker
    volumes:
      - "./tmp/localstack:/tmp/localstack"
      - "/var/run/docker.sock:/var/run/docker.sock"
```

### Environment

```markdown
- OS: MacOS BigSur
- LocalStack: `1dc090777b0c`
```


### Anything else?

This will try **only once** and put the message into DLQ after failure **although** the retry policy instructs for **3 retries**. This is the issue.

```bash
aws --profile localstack --endpoint-url http://localhost:4566 lambda create-function \
    --function-name api-lambda \
    --handler lambda/main \
    --runtime go1.x \
    --role api-role \
    --zip-file fileb://lambda.zip
    
aws --profile localstack --endpoint-url http://localhost:4566 sqs create-queue \
    --queue-name api-dead-letter-queue

aws --profile localstack --endpoint-url http://localhost:4566 sqs create-queue \
    --queue-name api-queue \
    --attributes '{"RedrivePolicy":"{\"deadLetterTargetArn\":\"arn:aws:sqs:eu-west-1:000000000000:api-dead-letter-queue\",\"maxReceiveCount\":\"3\"}"}'

aws --profile localstack --endpoint-url http://localhost:4566 lambda create-event-source-mapping \
    --function-name api-lambda \
    --event-source-arn arn:aws:sqs:eu-west-1:000000000000:api-queue
```

Use this command to test.

```bash
aws --profile localstack --endpoint-url http://localhost:4566 sqs send-message \
    --queue-url http://localhost:4566/000000000000/api-queue \
    --message-body '{"hello":"world"}'
```

----

FYI - This will try **indefinitely** (_30 sec in between_) until it succeeds because there is **no** retry policy set which is perfectly normal and expected behaviour.

```bash
aws --profile localstack --endpoint-url http://localhost:4566 lambda create-function \
    --function-name api-lambda \
    --handler lambda/main \
    --runtime go1.x \
    --role api-role \
    --zip-file fileb://lambda.zip
    
aws --profile localstack --endpoint-url http://localhost:4566 sqs create-queue \
    --queue-name api-dead-letter-queue

aws --profile localstack --endpoint-url http://localhost:4566 sqs create-queue \
    --queue-name api-queue

aws --profile localstack --endpoint-url http://localhost:4566 lambda create-event-source-mapping \
    --function-name api-lambda \
    --event-source-arn arn:aws:sqs:eu-west-1:000000000000:api-queue
```
)
                    try:
                        result = self._execute(lambda_function, inv_context)
                    except Exception as e:
                        raised_error = e
                        dlq_sent = handle_error(lambda_function, event, e, asynchronous)
                        raise e
                    finally:
                        self.function_invoke_times[func_arn] = invocation_time
                        callback and callback(
                            result, func_arn, event, error=raised_error, dlq_sent=dlq_sent
                        )
                        lambda_result_to_destination(
                            lambda_function, event, result, asynchronous, raised_error
                        )
                    
                    return result
            return _run(func_arn=func_arn)
        
        if asynchronous:
            LOG.debug(
                "Lambda executed in Event (asynchronous) mode, no response will be returned to caller"
            )
            FuncThread(do_execute).start()
            return InvocationResult(None, log_output="Lambda executed asynchronously.")
        return do_execute()
    def _execute(self, lambda_function: LambdaFunction, inv_context: InvocationContext):
        """This method must be overwritten by subclasses."""
        raise NotImplementedError
    def startup(self):