Float32 degrees and Int radians is promoted to Float64

`promote(1f0°, 2rad)` returns a `Float64` pair, while many other combinations of `Float32` and `Int` arguments are promoted to a (imho correct) `Float32` pair.

```julia
julia> promote(1f0°, 2rad)
(0.01745329238474369, 2.0)

julia> promote(1f0, 2)
(1.0f0, 2.0f0)

julia> promote(1f0°, 2)
(0.017453292f0, 2.0f0)
```

Reproduce the three `promote` examples from the issue, then trace the promotion methods handling a `Float32` degree value with an `Int` radian value. Done means the degree-and-radian combination promotes to a `Float32` pair consistently with the other shown combinations, with tests covering the behavior.

Written by the indexing model from the issue text.