Commands used to generate the tiff:
```
sed 's/${PACKAGE_NAME}/Bitcoin ABC/' contrib/macdeploy/background.svg.cmake.in > background.svg
rsvg-convert -f png -d 36 -p 36 background.svg -o background_temp.png
rsvg-convert -f png -d 72 -p 72 background.svg -o background_temp@2x.png
convert background_temp.png background_temp.tiff
convert background_temp@2x.png background_temp@2x.tiff
tiffcp -c none background_temp.tiff background_temp@2x.tiff background.tiff
```
This is a backport of core#23909
Depends on D13956