Narrowed the docfx assembly build to just the needed package production assembly

Author: kzdev-net

.github/workflows/docfx-publish.yml

@@ -31,7 +31,7 @@ jobs:
           dotnet-version: 9.x
 
       - run: dotnet restore Source/KZDev.PerfUtils.sln
-      - run: dotnet build -c Release Source/KZDev.PerfUtils.sln
+      - run: dotnet build -c Release Source/Src/KZDev.PerfUtils/KZDev.PerfUtils.csproj
       - run: dotnet tool update -g docfx
       - run: docfx Source/Docs/docfx.json