[CNCF Incubation] [Security] Submit security self-assessment snapshot to cncf/toc

[kfaseela]

Please submit a snapshot of the completed security self-assessment (docs/security/self-assessment.md) to cncf/toc at projects/cozystack/security-assessment/self-assessment.md, per the Security section of the incubation due diligence guide.

Related to the incubation application.

[tym83]

Submitted the security self-assessment snapshot as a PR against cncf/toc: cncf/toc#2306, adding projects/cozystack/security-assessment/self-assessment.md. It is a point-in-time copy of docs/security/self-assessment.md from cozystack/cozystack.