Unity 2021.3.17f1 spams line ending warnings when loading the built Cesium for Unity

[kring]

For example:

There are inconsistent line endings in the 'Packages/com.cesium.unity/Editor/generated/Reinterop/Reinterop.RoslynSourceGenerator/CesiumIonSession-generated.cs' script. Some are Mac OS X (UNIX) and some are Windows.
This might lead to incorrect line numbers in stacktraces and compiler errors. Many text editors can fix this using Convert Line Endings menu commands.

This happens because we generate code on different platforms, and then smash them together with ifdefs. We should normalize the line endings as part of the build process.