sunset ibbtc msig

[gosuto-inzasheru]

• [x] #204
• [x] #276
• [x] decide on how to distribute the claimed rewards; some are from the bvecvx stuck in the peak, some are from the bcrvrenwbtc holdings
• [ ] add dev msig as owner, set threshold to 1, remove all other owners

also we can close https://github.com/Badger-Finance/badger-avatars/issues/1 since it will no longer be needed

[gosuto-inzasheru]

in order to fully deprecate a msig, i am suggesting to make it a 1/1 msig with dev as a single signer