Update BC DevTools setup for netstandard2.0 and net8.0 - #7

Possible null reference argument for parameter 'source' in 'string? Enumerable.FirstOrDefault<string>(IEnumerable<string> source, Func<string, bool> predicate)'.

Possible null reference argument for parameter 'path' in 'PortableExecutableReference MetadataReference.CreateFromFile(string path, MetadataReferenceProperties properties = default(MetadataReferenceProperties), DocumentationProvider? documentation = null)'.

Possible null reference argument for parameter 'source' in 'string? Enumerable.FirstOrDefault<string>(IEnumerable<string> source, Func<string, bool> predicate)'.

Possible null reference return.

Dereference of a possibly null reference.