### 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.
# cr
        # wr
        bucket_name = s3_create_bucket(ObjectLockEnabledForBucket=True)
        resp = aws_client.s3.put_(
            Bucket=bucket_name,
            Key=_key,
            Body='{"key": "value"}',
            ObjectLockLegalHoldStatus="ON",
        )
        snapshot.match("put_", resp)
        head_ = aws_client.s3.head_(Bucket=bucket_name, Key=_key)
        snapshot.match("head_", head_)
        resp = aws_client.s3.copy_(
            Bucket=bucket_name,
            CopySource=f"{bucket_name}/{_key}",
            Key=dest_key,
        )
        snapshot.match("copy-legal-hold", resp)
        # th
        head_ = aws_client.s3.head_(Bucket=bucket_name, Key=dest_key)
        snapshot.match("head-dest-key", head_)
        # di
        for key in (_key, dest_key):
            with contextlib.suppress(ClientError):
                aws_client.s3.put__legal_hold(
                    Bucket=bucket_name, Key=key, LegalHold={"Status": "OFF"}
                )
    @pytest.mark.aws_validated
    @pytest.mark.skip_snapshot_verify(paths=["$..ServerSideEncryption"])
    def test_s3_copy__lock(self, s3_create_bucket, snapshot, aws_client):