upperBoundExclusiveToUpperBoundInclusive()

If a Postgres range type has a well-defined step, Postgres automatically converts it to a canonical form. Types such as int4range get converted to upper-bound-exclusive. This method is needed when converting an upper bound to inclusive. It should throw if the type lacks a well-defined step.

func upperBoundExclusiveToUpperBoundInclusive() throws -> Self