bug: worst case share indexes uses max square size

[rootulp]

Context

go-square/square/builder.go

Line 414 in a841739

func worstCaseShareIndexes(blobs, maxSquareSize int) []uint32 {

Problem

We want worstCaseShareIndexes to always use the upper bound for max square size (128) so that celestia-node doesn't have to be stateful when extending the ODS.

If worstCaseShareIndexes uses the max effective square size (64) then celestia-node would have to poll celestia-app for the gov max square size every block.

Also note that celestia-app v1.x used a worstCaseShareIndexes of 128 so it was a consensus breaking change to drop down to 64.

Proposal

Modify the second argument to this function to use the upper bound of 128

[rootulp]

FWIW I think this issue has existed since go-square was extracted from celestia-app. See 68863fc#diff-f37b1db98350d69502a30f6f3dd88ae2f6844b2bb6e0c46f89d3b6a237788b3cR414

[rootulp]

I just thought of a way to fix this bug without introducing an API breaking change, will publish an alternative PR soon.