Bump Microsoft.CodeAnalysis.CSharp and Microsoft.CodeAnalysis.CSharp.Workspaces - #304

Possible null reference argument for parameter 'args' in 'void ILogger.Information(string messageTemplate, params object[] args)'.

Non-nullable property 'OutputDirectoryName' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'ReferencesDirectoryName' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Name' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Name' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Namespace' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(byte[], byte[], int)' is obsolete: 'The constructors on Rfc2898DeriveBytes are obsolete. Use the static Pbkdf2 method instead.' (https://aka.ms/dotnet-warnings/SYSLIB0060)

'Rfc2898DeriveBytes.Rfc2898DeriveBytes(byte[], byte[], int)' is obsolete: 'The constructors on Rfc2898DeriveBytes are obsolete. Use the static Pbkdf2 method instead.' (https://aka.ms/dotnet-warnings/SYSLIB0060)

Dereference of a possibly null reference.