This adds a new app icon for windows that is less Mac-like and it also
fixes a bug in the electron-builder.config.cjs file which would cause
the packaging step to crash if it was missing the signing env vars,
rather than just not signing the package.
![image](https://github.com/user-attachments/assets/fe433ae5-0b88-49a9-91b6-d1083460b7b2)