mining_proxy_sv2 deprecation

[plebhash]

this crate introduces a lot of abstraction overhead as a requirement for roles_logic_sv2

we're not aware of any adopter needing something like this for the near horizon

should we kill this crate and make things simpler?

we could always refer to git history if we need to look at it as reference someday, but I feel we kind of need a clean canvas for our progress on roles_logic_sv2 to really flourish

[jbesraa]

Yes please.

[plebhash]

mining_proxy_sv2 was deprecated via #1765