Fix for the average Pixel diff not being what we expected.

Diffs=
8178dd7936 fix for imagediff avrg being wrong (#8430)

`libgms.a` `libgoldens.a` `libtools_common.a` now building for unreal on Mac and iOS. `build-rive.py` now runs correctly on Mac for Mono Repo.
Unreal GM Plugin now correctly loads and fixed decoder to use correct symbols independent of platform.

Diffs=
c64659be84 Make build script work on mac (#8421)

First steps towards supporting artboard resizing in our runtimes. This PR includes:
- New Fit type `autoResizeArtboard`. After a bit of back and forth, I think this keeps the API simple.
- ScaleFactor which represents a scale value to scale the artboard by in addition to resizing (only applies with `autoResizeArtboard`). This may be useful because an artboard is created at a specific width/height, but it may be deployed to platforms where it is rendered to a much smaller or larger surface/texture. Currently the default is 1.0 (no scale), however, an alternative is to have it default to something like textureSize / artboardSize so we sort of auto normalize it.
- Implemented on iOS. Once this is finalzed, we can work with DevRels to implement across all runtimes.
- TODO : Bubble up an event when the artboard size is changed internally by the .riv

https://github.com/user-attachments/assets/20e9fdda-5c3e-4f3f-b2f5-104ff0291fbe

Diffs=
e71b4cc081 feat: add runtime layout fit type for ios, android, web (#8341)

Co-authored-by: CI <[email protected]>
Co-authored-by: David Skuza <[email protected]>
Co-authored-by: Philip Chung <[email protected]>

Give Draws more control over exactly where their tessellations go, instead of having the renderContext do it automatically. This will allow for more elaborate splitting up into prepasses/subpasses and reordering. Make the RenderContext API for generating tessellations more flexible about specifying where the vertices go.

Diffs=
ea59076bf7 Expose RenderContext methods for allocating tessellation vertices (#8408)