upgrade to net8.0 (#2) * upgrade to net8.0 * use sdk version 8.0.112 in global.json * upgrade Microsoft.IdentityModel.Protocols.OpenIdConnect to 7.1.2 * use net sdk 8.0.405 * use net sdk 8.0.* * use System.IdentityModel.Tokens.Jwt 7.1.2 * IsNullOrEmpty() * use System.IdentityModel.Tokens.Jwt 8.3.1 * String -> var, invalid_request -> invalid_request_object * remove trailing comma from jsonwebkey json * amend another set of unit tests * Parameter mismatch in JWT request -> Invalid JWT request * double-quotes in json string * amend error responses * amend error responses * update automapper * Mapper: change to non-generic method * revert ISystemClock * System.Security.Principal.Windows 4.7.0 -> 5.0.0 * upgrade Newtonsoft.Json to 13.0.3 * test ISystemClock -> TimeProvider * revert test ISystemClock -> TimeProvider