CI build failing after M.E.AI.Evaluations merging

[stephentoub]

CSC : error CS1566: Error reading resource 'Reporting.HTML.index.html' -- 'Could not find a part of the path 'D:\a\_work\1\s\src\Libraries\Microsoft.Extensions.AI.Evaluation.Reporting\TypeScript\html-report\dist\index.html'.' [D:\a\_work\1\s\src\Libraries\Microsoft.Extensions.AI.Evaluation.Reporting\CSharp\Microsoft.Extensions.AI.Evaluation.Reporting.csproj::TargetFramework=net8.0]
##[error]CSC(0,0): error CS1566: (NETCORE_ENGINEERING_TELEMETRY=Build) Error reading resource 'Reporting.HTML.index.html' -- 'Could not find a part of the path 'D:\a\_work\1\s\src\Libraries\Microsoft.Extensions.AI.Evaluation.Reporting\TypeScript\html-report\dist\index.html'.'

e.g. https://dev.azure.com/dnceng-public/public/_build/results?buildId=951692&view=logs&jobId=0bc77094-9fcd-5c38-f6e4-27d2ae131589&j=0bc77094-9fcd-5c38-f6e4-27d2ae131589&t=e2f678a7-b875-5c17-f40e-3e55bcefed52

cc: @peterwald, @shyamnamboodiripad

[peterwald]

Similar to (and maybe the same as #5900). I see in this case, msbuild is not waiting until the node script completes before continuing the build. So the output file is not available until after the compiler requires it.