ci: allow notify dd release job to fail (#17709)

## Description

Allowing failure to keep release pipelines green

## Testing

<!-- Describe your testing strategy or note what tests are included -->

## Risks

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## Additional Notes

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Co-authored-by: gyuheon.oh <gyuheon.oh@datadoghq.com>

Author: gyuheon0h

.gitlab/release.yml

@@ -45,6 +45,7 @@ release_pypi_prod:
 
 notify_datadog_release:
   extends: .release_base
+  allow_failure: true
   needs: [ "ddtrace package", "release_pypi_prod" ]
   image: ${PYPI_PUBLISH_IMAGE}
   id_tokens: