Bump external/nextflow-config from 1960eaa to da8e990

Bumps [external/nextflow-config](https://github.com/uclahs-cds/pipeline-Nextflow-config) from `1960eaa` to `da8e990`.
- [Release notes](https://github.com/uclahs-cds/pipeline-Nextflow-config/releases)
- [Commits](uclahs-cds/pipeline-Nextflow-config@1960eaa...da8e990)

---
updated-dependencies:
- dependency-name: external/nextflow-config
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>