CI failure with package restore

This failure occurred in CI on https://github.com/dotnet/aspnetcore/pull/48957.

```
D:\a\_work\1\s\.dotnet\sdk\8.0.100-preview.6.23305.3\NuGet.targets(156,5): error : Cannot create a file when that file already exists. [D:\a\_work\1\s\src\Grpc\JsonTranscoding\test\testassets\Sandbox\Sandbox.csproj]
##[error].dotnet\sdk\8.0.100-preview.6.23305.3\NuGet.targets(156,5): error : (NETCORE_ENGINEERING_TELEMETRY=Build) Cannot create a file when that file already exists.
```

I re-ran the leg to get the PR through, but didn't find a prior issue for this type of failure so I'm creating this to track it.