ArbitrumDAO Proposes DVP Quorum Upgrade and Cancellation

ArbitrumDAO proposes DVP Quorum upgrade and onchain proposal cancellation. Quorum set as min{max quorum, max{ɑ*DVP, baseline quorum}} with ɑ=0.5/0.4, baseline quorum 150m/100m ARB, max quorum 450m/300m ARB for constitutional/non-constitutional. Proposal creators can cancel within 3-day pending period via cancel() on upgraded Core and Treasury Governor contracts. Constitution hash updates accordingly.