newStencilMode null dereference

[louwers]

With my CMake build I am hitting a problem where newStencilMode in the Metal drawable.cpp is dereferenced when it is null:

maplibre-native/src/mbgl/mtl/drawable.cpp

Line 255 in 3acfd02

impl->previousStencilMode = *newStencilMode;

To reproduce check out #3234 (or after it is merged)

cmake --preset ios
xed build-ios/MapLibre\ Native.xcodeproj

Run app target.

Maybe @TimSylvester can have a look.