Remove auto-inference of attribute divisor

[Pessimistress]

https://github.com/uber/luma.gl/blob/master/modules/webgl/src/classes/program-configuration.js#L108

See https://github.com/uber/deck.gl/pull/2919

[tsherif]

@Pessimistress This should be an easy fix. Any concerns about breakage elsewhere?

[ibgreen]

Worth running luma examples.

Updating title to be more specific: Remove auto-inference of attribute types => Remove auto-inference of attribute divisor.

At this stage I would only remove the divisor inference as it is a heuristic (as opposed to being based on a query of the compiled shader).