chore(deps) Update dependency markdown-it to v15 - #778

Remove this commented out code.

'SqlConnection' is obsolete: 'Use the Microsoft.Data.SqlClient package instead.'

'SqlConnection' is obsolete: 'Use the Microsoft.Data.SqlClient package instead.'

'SqlConnectionStringBuilder' is obsolete: 'Use the Microsoft.Data.SqlClient package instead.'

'SqlException' is obsolete: 'Use the Microsoft.Data.SqlClient package instead.'

'AuthenticationHandler<TestSsoSchemeOptions>.AuthenticationHandler(IOptionsMonitor<TestSsoSchemeOptions>, ILoggerFactory, UrlEncoder, ISystemClock)' is obsolete: 'ISystemClock is obsolete, use TimeProvider on AuthenticationSchemeOptions instead.'

'AuthenticationHandler<DemoSchemeOptions>.AuthenticationHandler(IOptionsMonitor<DemoSchemeOptions>, ILoggerFactory, UrlEncoder, ISystemClock)' is obsolete: 'ISystemClock is obsolete, use TimeProvider on AuthenticationSchemeOptions instead.'

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

'ISystemClock' is obsolete: 'Use TimeProvider instead.'