Update Privileged Roles

[cpengilly]

Flagging a quick docs update for privileged roles

I believe we want to update the standard config spec so L2 ProxyAdmin owner is required to be the aliased address of the L1 ProxyAdmin Owner. We also currently incorrectly state in both the https://specs.optimism.io/protocol/configurability.html#admin-roles and https://docs.optimism.io/chain/security/privileged-roles#l2-proxy-admin that the L2 ProxyAdmin owner is a Foundation Safe on L2, but now that Upgrade 8 is executed it's actually 0x6B1BAE59D09fCcbdDB6C6cceb07B7279367C4E3b, which is the aliased L1 Safe address.