Update Code of Conduct contact email

[nvliyuan]

Summary

• replace the Spark RAPIDS conduct email with the cuDF Spark conduct distribution list
• update both the displayed address and mailto link

Test plan

• Verified the Code of Conduct references cudf-spark-conduct@nvidia.com

[greptile-apps]

Greptile Summary

Updates the Code of Conduct’s incident-reporting contact from the Spark RAPIDS address to the cuDF Spark conduct distribution list.

• Replaces the displayed email address.
• Updates the matching mailto link.

Confidence Score: 5/5

The PR appears safe to merge.

The documentation-only change consistently updates both the visible conduct address and its mail link, with no behavioral or security issues identified.

Important Files Changed

Filename	Overview
CODE_OF_CONDUCT.md	The enforcement contact and its mailto target are consistently updated to cudf-spark-conduct@nvidia.com.

_{Reviews (1): Last reviewed commit: "Update Code of Conduct contact email" | Re-trigger Greptile}