[CNCF TOC] Archive OpenCurve Project

[angellk]

@aspirer @ilixiaocui @opencurveadmin

It looks like work on the OpenCurve project stopped in December, 2023.

Please confirm OpenCurve's current status by October 18, 2024. At that time the project will be moved to a vote to archive. If active development resumes on the project, the OpenCurve project may resubmit to apply for CNCF Sandbox.

xref: cncf/toc#1449