Property Validation: `exclusiveMaximum`

The `exclusiveMaximum` constraint on a property enforces that the value is _up to but not including_ the maximum constraint.

Changing from an inclusive maximum to an exclusive maximum would be a breaking change as it shrinks the range of allowed values and thus breaks client/user expectations and may invalidate existing instances that use the inclusive maximum value.

Going from an exclusive maximum to an inclusive maximum would generally be OK as you would be expanding the range of allowed values and not be invalidating existing instances or client/user expectations of existing values that would work.