### 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.
)
        # AWS 
        exception = xmltodict.parse(response.content)
        exception["StatusCode"] = response.status_code
        snapshot.match("exception-missing-signature", exception)
    @pytest.mark.aws_validated
    @pytest.mark.xfail(
        condition=LEGACY_S3_PROVIDER, reason="Policy is not validated in legacy provider"
    )
    @pytest.mark.parametrize(
        "signature_version",
        ["s3", "s3v4"],
    )
    def test_post_request_missing_fields(
        self,
        s3_bucket,
        snapshot,
        signature_version,
        patch_s3_skip_signature_validation_false,
        aws_client,
    ):
        snapshot.add_transformer(self._get_presigned_snapshot_transformers(snapshot))
        _key = "test-presigned-missing-fields"
        presigned_client = _s3_client_custom_config(
            Config(signature_version=signature_version),
            endpoint_url=_endpoint_url(),
        )
        presigned_request = presigned_client.generate_presigned_post(
            Bucket=s3_bucket, Key=_key, ExpiresIn=60
        )