Incorrect permutation length in validateVKPermuationsLength

[zeroqn]

Describe the bug

The error arises from the range check lookup table. For instance, when the balanceByteRange is set to 9, we expect to have four 2^16 lookup tables plus an additional 2^8 or 2^16 lookup table. balanceByteRange / 2 return 4, which is wrong.

To Reproduce

change balanceByteRange to 9
https://github.com/summa-dev/summa-solvency/blob/v2/contracts/test/Summa.ts#L43

Expected behavior

test should fail

Additional context