Whitelisted by: https://kusama.subsquare.io/fellowship/referenda/90

This referenda increases the parachain validator set size from 500 to 600.
The maximum backing group size is kept to 5, so the total number of usable cores increases to 120.

Additionally, also update the setNDelayTranches from 89 to 257, which will reduce the number of assignments per candidate per delay tranche from ~5.61 to ~2.33, the justification why this is the desired value for this parameter can be found in ELVES https://eprint.iacr.org/2024/961 paper and here https://github.com/paritytech/polkadot-sdk/issues/6853#issuecomment-2540373492.