feat: update max bond gas to 300m (#148)

Updates max bond gas charged to 300m up from 200m. Corresponds to
recent changes in the large preimage solution.

specs/experimental/fault-proof/stage-one/bond-incentives.md

@@ -93,17 +93,17 @@ For the moment, we suppose that the `Guardian` address may account for increased
 FPM bonds are priced in the amount of gas that they are intended to cover.
 Bonds start at the very first depth of the game at a baseline of `400_000` gas.
 The `400_000` value is chosen as a deterrence amount that is approximately double the cost to respond at the top level.
-Bonds scale up to a value of `200_000_000` gas, a value chosen to cover approximately double the cost of a max-size
+Bonds scale up to a value of `300_000_000` gas, a value chosen to cover approximately double the cost of a max-size
 Large Preimage Proposal.
 
 We use a multiplicative scaling mechanism to guarantee that the ratio between bonds remains constant.
 We determine the multiplier based on the proposed `MAX_DEPTH` of 73.
-We can use the formula `x = (200_000_000 / 400_000) ** (1 / 73)` to determine that `x = 1.089`.
-At each depth `N`, the amount of gas charged is therefore `400_000 * (1.089 ** N)`
+We can use the formula `x = (300_000_000 / 400_000) ** (1 / 73)` to determine that `x = 1.09493`.
+At each depth `N`, the amount of gas charged is therefore `400_000 * (1.09493 ** N)`
 
 Below is a diagram demonstrating this curve for a max depth of 73.
 
-![bond scaling curve](https://github.com/ethereum-optimism/specs/assets/14298799/acc02dd8-1b7a-4c1d-9c44-4abdc0965d52)
+![bond scaling curve](https://github.com/ethereum-optimism/specs/assets/14298799/b381037b-193d-42c5-9a9c-9cc5f43b255f)
 
 ### Required Bond Formula
 
@@ -114,7 +114,7 @@ Applying the [Base Fee Assumption](#base-fee-assumption) and [Bond Scaling](#bon
 def get_required_bond(position):
     assumed_gas_price = 200 gwei
     base_gas_charged = 400_000
-    gas_charged = 400_000 * (1.089 ** position.depth)
+    gas_charged = 400_000 * (1.09493 ** position.depth)
     return gas_charged * assumed_gas_price
 ```