Test upgrade v3 to v4 on v4.0.0-rc0

[rootulp]

Context

Prior to creating v4.0.0-arabica, we should test v4.0.0-rc0

Proposal

• Upgrade a local testnet from v3 to v4 using v4.0.0-rc0 (chore: fix single-node-upgrades.sh #4640)
• Upgrade a local testnet from v3 to v4 using v40.0.-rc0 with bridge nodes. Blocked on a release of celestia-node that is compatible with v4.0.0-rc0. See deps: Bump SDK to version 0.50 and Celestia App to V4 celestia-node#4219

[rootulp]

Tested a local v3 to v4 upgrade with #4640

Testing with bridge nodes is blocked on a celestia-node release with celestiaorg/celestia-node#4219

[rootulp]

Tracking the incomplete action item in #4682