Build debugger-libs as a submodule throws nugets not found errors..

[CartBlanche]

@thaystg et al...
I've just updated our debugger-libs submodule to point to the the latest commit, 35ab1bd2c237c155296749fa0a680ce5d4f2e13d, on main
When Github Action CI tries to build the required *.csprojs I get the following errors.

D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\src\csharp\VSCodeMeadow.csproj : error NU1101: Unable to find package Microsoft.SymbolStore. No packages exist with this id in source(s): C:\Program Files\dotnet\library-packs, nuget.org
                     D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\src\csharp\VSCodeMeadow.csproj : error NU1101: Unable to find package Microsoft.FileFormats. No packages exist with this id in source(s): C:\Program Files\dotnet\library-packs, nuget.org
                     D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\externals\debugger-libs\Mono.Debugger.Soft\Mono.Debugger.Soft.csproj : error NU1101: Unable to find package Microsoft.SymbolStore. No packages exist with this id in source(s): C:\Program Files\dotnet\library-packs, nuget.org [D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\src\csharp\VSCodeMeadow.csproj]
                     D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\externals\debugger-libs\Mono.Debugger.Soft\Mono.Debugger.Soft.csproj : error NU1101: Unable to find package Microsoft.FileFormats. No packages exist with this id in source(s): C:\Program Files\dotnet\library-packs, nuget.org [D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\src\csharp\VSCodeMeadow.csproj]
                     D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\externals\debugger-libs\Mono.Debugging.Soft\Mono.Debugging.Soft.csproj : error NU1101: Unable to find package Microsoft.SymbolStore. No packages exist with this id in source(s): C:\Program Files\dotnet\library-packs, nuget.org [D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\src\csharp\VSCodeMeadow.csproj]
                     D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\externals\debugger-libs\Mono.Debugging.Soft\Mono.Debugging.Soft.csproj : error NU1101: Unable to find package Microsoft.FileFormats. No packages exist with this id in source(s): C:\Program Files\dotnet\library-packs, nuget.org [D:\a\VSCode_Meadow_Extension\VSCode_Meadow_Extension\main\src\csharp\VSCodeMeadow.csproj]

    3 Warning(s)
    6 Error(s)

Any tips on how to resolve this? Pointing to an old submodule commit never threw these errors, but we want the latest debugger library fixes :)