Try adding <ExcludeAssets> runtime </ExcludeAssets>
to the <PackageReference>
:
<ItemGroup Condition="'$(TargetFramework)' == 'net7.0-windows'">
<PackageReference Include="Grasshopper" Version="8.0.23304.9001">
<ExcludeAssets> runtime </ExcludeAssets>
</PackageReference>
</ItemGroup>
<ItemGroup Condition="'$(TargetFramework)' == 'net48'">
<PackageReference Include="Grasshopper" Version="7.0.20314.3001">
<ExcludeAssets> runtime </ExcludeAssets>
</PackageReference>
</ItemGroup>