Unable to build all projects in solution on the winui branch

[marcelwgn]

When using the winui branch, building the solution wth VS 2022 ends with a few projects failing to build. Build log: https://gist.github.com/chingucoding/5fd6d1cdf7b9e6fd297ce6a2c032b236

Context: I was trying to figure out why unit test projects for WinUI 3 were not working and the awesome @azchohfi suggested to checkout the winui branch and it's unit tests. Since building (and running them didn't work), I'm opening this issue for input and help.