Prop 34: Upgrade to agoric-upgrade-10

This proposal if voted will upgrade the chain to agoric-upgrade-10
## Upgrade Features
This release contains a number of significant upgrades and new features including:
- Vaults contracts
- Validator State Sync
- Smart Contract Upgradeability
- Governance Capability Upgrade
- Decentralized Oracle Network
- Critical Message Prioritization
- Scalability and Performance Improvements.
## Discussion
https://community.agoric.com/t/agoric-upgrade-10-mainnet-1b-upgrade/286
## Release
https://github.com/Agoric/agoric-sdk/releases/tag/mainnet1B-rc3
## Details of Upgrade Time
The proposal targets the upgrade proposal block to be 10403035, anticipated to be on June 19th 2023 at 17:00 UTC.
Because blocks can occur at irregular intervals, please keep an eye on the Agoric chain for a precise upgrade time.