Write RAP team policy for dependency updates

[madwort]

See this thread.

wip document

[madwort]

Mike to collate all our notes into a second draft

[madwort]

Mike has created a second draft, I've left a few notes, I think it's basically done, he's going to circulate to increasingly wider groups of people for comment.

[madwort]

Had another meeting today with Mike today, addressing comments from the most recent round of feedback. We think the policy is now basically ready to send to BenBC for adoption.

Current version:

https://docs.google.com/document/d/1s1zQ_312d7Fy89j5H8AHJSCeLK-rLBBls3XIQJGP9fw/edit?tab=t.0#heading=h.nmecvlmclkww