Fixing MSBuild TARGETPATH Issue

Ran into an issue that was causing the following error on GitLab when trying to build a package:

/usr/share/dotnet/sdk/7.0.103/Sdks/NuGet.Build.Tasks.Pack/build/NuGet.Build.Tasks.Pack.targets(221,5): error NU5026: The file '${TARGETPATH}' to be packed was not found on disk. [/hugo servbuilds/organization/My.Project/My.Project/My.Project.csproj]

The solution is to define TargetPath explicitly in all .csproj files by adding a PropertyGroup section like so:

<!-- fixes TARGETPATH issue -->