[Track] ensure compliance to the CNCF to get machine sponsorship from external

[sunya-ch]

Currently in kepler-metal-ci project, CI for training and validating kepler power model, we have Equinix metal server sponsored by CNCF and AWS e2 instance from @rootfs's account.
However, as mentioned in #1906, we do need more variation of machines and sensors to extend coverage of our Kepler on Cloud use case.

This issue is to investigate how could we get more machine sponsors to the Kepler project in the right process under CNCF umbrella.

Action items

• investigating what against the compliance and what is not
• investigating who calls for sponsorships - via Kepler community or CNCF or LF?
• listing in-demand machines/sensors (e.g., from [Track] Call for Machine/Device Sponsorship #1906 (comment))
• listing requirements for machines (e.g., must be supported by gh self-hosted runners)
• listing requirements for access (what sponsors have to provide e.g., access key to self-hosted runner)
• listing recognition items we can return