### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

The Complete Multipart Upload operation generates the **InternalError** error for non-existing uploads.

### Expected Behavior

The Complete Multipart Upload operation generates the **NoSuchUpload** error for non-existing uploads.

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

    docker run -it --rm -p 4566:4566 localstack/localstack

    aws s3api create-bucket --bucket test --endpoint-url http://localhost:4566 --create-bucket-configuration LocationConstraint=us-west-2

    aws s3api complete-multipart-upload --bucket test --endpoint-url http://localhost:4566 --key test --upload-id test

### Environment

```markdown
- OS: Windows 11
- LocalStack: latest
```


### Anything else?

The Abort Multipart Upload operation works correctly in LocalStack.

The official documentation: https://docs.aws.amazon.com/AmazonS3/latest/API/API_CompleteMultipartUpload.html
Amazon S3 throws the correct **NoSuchUpload** error for both Abort and Complete operations.
snapshot.add_transformer(snapshot.transform.key_value("BucketName"))
        with 
            aws_client.s3.get_(Bucket=f"does-not-exist-{short_uid()}", Key="foobar")
        snapshot.match("expected_error", e.value.response)
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(condition=is_old_provider, path="$..RequestID")
    def test_delete_bucket_no_such_bucket(self, snapshot, aws_client):
        with 
            aws_client.s3.delete_bucket(Bucket="does-not-exist-localstack-test")
        snapshot.match("expected_error", e.value.response)
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(condition=is_old_provider, path="$..Error.BucketName")
    def test_get_bucket_notification_configuration_no_such_bucket(self, snapshot, aws_client):
        snapshot.add_transformer(snapshot.transform.key_value("BucketName"))
        with 
            aws_client.s3.get_bucket_notification_configuration(
                Bucket=f"doesnotexist-{short_uid()}"
            )
        snapshot.match("expected_error", e.value.response)
    @pytest.mark.aws_validated
    @pytest.mark.xfail(
        condition=LEGACY_S3_PROVIDER,
        reason="currently not implemented in moto, see https://github.com/localstack/localstack/issues/6217",
    )
    def test_get__attributes(self, s3_bucket, snapshot, s3_multipart_upload, aws_client):