Windows Clang 18 fixes

This fixes the issues that prevent Clang 18 from compiling the game on windows. FMT 10.2.x was also needed for a windows only issue. Clang 19 would need more work.

I have a CI job on my test-x86-clang-win branch, but it needs cleanup and ccache doesn't seem to work correctly. If preferred I can add that to this MR.