Update njs to 0.9.1

[agebhar1]

Proposed changes

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Checklist

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• [X] I have read the contributing guidelines
• [X] I have signed the F5 Contributor License Agreement (CLA)
• [X] I have run ./update.sh and ensured all entrypoint/Dockerfile template changes have been applied to the relevant image entrypoint scripts & Dockerfiles
• [X] If applicable, I have added tests that prove my fix is effective or that my feature works
• [X] If applicable, I have checked that any relevant tests pass after adding my changes
• [X] I have updated any relevant documentation (README.md and/or modules/README.md)