Penumbra voluntary halt and upgrade in response to IBC dependency fix

This upgrade is consensus-breaking, and adopts a liveness bug fix to an IBC dependency that the Penumbra protocol depends on.

Voting for this proposal signals agreement and readiness by the community of validators supporting the Penumbra chain to standby for an upcoming software patch upon halt at a predetermined height.

Penumbra validators should be expected to momentarily halt the chain at height 4378762, standby, and adopt a new version of the Penumbra software disseminated in response to the IBC path in order to reinitialize the Penumbra chain upon release of new software.

• Deposit amount100 UM