.NET 9.0.10x SDK breaks build that worked in 8.0.405 with missing apphost.exe

[AArnott]

We have a repo where we pin the SDK, so we have exact control over which SDK is used.
When we update from 8.0.405 to 9.0.102 (we also tried 9.0.100), the build fails with this error:

C:\ToolCache\dotnet\sdk\9.0.100\Microsoft.Common.CurrentVersion.targets(5322,5): error MSB3030: Could not copy the file "D:\a_work\1\s\obj\src\Microsoft.VisualStudio.Code.Server\x86\Release\apphost.exe" because it was not found. [D:\a_work\1\s\src\Microsoft.VisualStudio.Code.Server\Microsoft.VisualStudio.Code.Server.csproj]

I believe it's a non-deterministic target ordering issue, because once I got the build to pass locally, but all the other times it failed. When it passed, the apphost.exe file was on the disk in the expected place.

binlog

The problem apparently goes away when we change our TargetFramework from net8.0 to net9.0. Not sure if that's a "stable" fix or just lucky due to the target ordering theory.