broken on nightly due to RangeInclusive change

[pnkfelix]

Compiler error:

error[E0223]: ambiguous associated type
   --> src/lit/src/grid.rs:106:13
    |
106 |             RangeInclusive::Empty { at } => PtRangeIterator {
    |             ^^^^^^^^^^^^^^^^^^^^^ ambiguous associated type
    |
    = note: specify the type using the syntax `<std::ops::RangeInclusive<_> as Trait>::Empty`

error[E0223]: ambiguous associated type
   --> src/lit/src/grid.rs:112:13
    |
112 |             RangeInclusive::NonEmpty { start, end } => PtRangeIterator {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^ ambiguous associated type
    |
    = note: specify the type using the syntax `<std::ops::RangeInclusive<_> as Trait>::NonEmpty`

This is due to the change from rust-lang/rust#42134