Function mz_repr::is_no_stats_type

pub fn is_no_stats_type(typ: &ScalarType) -> bool

This returns true if we don’t care to keep stats for this column type (for now). We’ll have to remove this if/when we start actually using the schema’d part encoding.

This is only used in tests, but we sadly can’t cfg(test) gate it because it’s also used from mz_storage_client tests.