nobridge flag for incompatible tokens

In my opinion the main purpose of this repository is to provide an index of `StandardBridge` compatible tokens. That is, tokens compatible with the `IOptimismMintableERC20` or `IL2StandardERC20` interfaces.

What we have instead is many 3rd party bridge tokens (Layer Zero OFTs, Wormhole NTTs, etc) that are not compatible with the native StandardBridge contracts but specify a bridge override. In my opinion these should be specify the `nobridge: true` flag so they don't show up in the generated [optimism.tokenlist.json](https://github.com/ethereum-optimism/ethereum-optimism.github.io/blob/master/optimism.tokenlist.json) file.

- If bridge frontends relying on this generated file correctly interpret the bridge override, the UX is that tokens show up but are not bridgeable

- If bridge frontends relying on this generated file don't account for the bridge override, losses can occur. Here are a few examples of this happening,

- 18 wstETH loss https://etherscan.io/tx/0x6c200205fc933c345cd7813e758934031478176e961ea56a1b8761b8534f761b
- 25 wstETH loss https://etherscan.io/tx/0x14c77dc75bf19e5eba3c6c5a853ad34430368f0746b4589d3ebfbbc57b8147b7
- $250,000 in SPX loss https://etherscan.io/tx/0x99092472f2c59e5f0881ee0560270761b84d10620daec2b9c08eae274537304f

Neither of these cases are desirable so I'd prefer if these were just automatically filtered out. I believe the CI checks used to enforce this, but they've been slightly altered and now if a bridge override is present it still allows adding tokens with a warning.

Start by locating the CI checks that validate bridge overrides and the generation path for optimism.tokenlist.json. Confirm how bridge overrides are currently handled, then verify that incompatible tokens using them are excluded when the nobridge flag is set and that the generated token list reflects this behavior.

Written by the indexing model from the issue text.