### 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("Location"),
                snapshot.transform.key_value("Bucket"),
            ]
        )
        key = "test.file"
        copy_key = "copy.file"
        src__path = f"{s3_bucket}/{key}"
        content = "test content 123"
        response = s3_multipart_upload(bucket=s3_bucket, key=key, data=content)
        snapshot.match("multipart-upload", response)
        multipart_etag = response["ETag"]
        response = aws_client.s3.copy_(
            Bucket=s3_bucket, CopySource=src__path, Key=copy_key
        )
        snapshot.match("copy-", response)
        copy_etag = response["CopyObjectResult"]["ETag"]
        # etag
        assert copy_etag != multipart_etag
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(condition=is_old_provider, paths=["$..VersionId"])
    def test_set_external_hostname(