update gas limit checks for Base

[tessr]

Base has experimented with pushing its gas limit beyond what is specified in the standard config.

Currently, this is fine: Since they’re not yet a standard chain, they aren’t bound by the recommended gas limit.

Long term, this should remain acceptable: The gas limit guideline exists to ensure chains maintain performance. Base has shown a commitment to responsible scaling, and their research will help us refine the standard config limits when they aim to become a standard chain.

The most recent update to the Base gas limit has officially pushed them over what’s permitted in the standard config. We’re currently checking this aggressively (but unnecessarily) for Base, so this is causing CI failures for the whole SCR.

To fix this, we should add an exception for Base to the gas limit checks, with a clear TODO to remove the exception when Base decides to adhere to the standard charter. We would like to maintain Base's status as a standard candidate in order to reflect their commitment to eventually becoming a standard chain.