[SECURITY] Emergency Governance: Delegate GTC to Veto Multisig

This is an extension to the "[SECURITY] Emergency Governance: Temporary Transition to Multisig Execution" proposal that delegates the 12,508,498.0957571 GTC in the Gitcoin DAO treasury to 0x5743e35477363241300fcedc2f5eb0195f300817 - which is a 4/5 multisig that can act as a veto for treasury attacks.

The delegates at 0x5743e35477363241300fcedc2f5eb0195f300817 would not weigh in on any vote except an attack on the treasury.

This action serves as a veto on any proposal thats below 13m GTC, increasing the cost of an attack to be at least (13m GTC + 3m GTC in currently active stewards) = 16m GTC.

https://tally.xyz/gov/gitcoin/proposal/19986480681679557869839903882420582374457431460979012393340892922945933213099