.NET 8.0 incompatibility with SecurityTokenValidators

[sherlock1982]

SecurityTokenValidators are obsolete and needs to be replaced with TokenHandlers

Noticed it because I need to use JwtServiceValidationHandler separately like this:
options.SecurityTokenValidators.Clear();
options.SecurityTokenValidators.Add(new JwtServiceValidationHandler(serviceProvider));

Added this for now to remove when addressed SecurityTokenValidators:
options.UseSecurityTokenValidators = true;

.NET make a warning here:
warning CS0618: 'JwtBearerOptions.SecurityTokenValidators' is obsolete: 'SecurityTokenValidators is no longer used by default. Use TokenHandlers instead. To continue using SecurityTokenValidators, set UseSecurityTokenValidators to true. See https://aka.ms/aspnetcore8/security-token-changes'

[brunobritodev]

PR #49