Ignore known exceptions from logging

[ikhoon]

Motivation:

Central Dogma does not use Armeria's LoggingClient, so known exceptions handled by HttpApiExceptionHandler are logged in DefaultUnloggedExceptionsReporter.

Moditications:

• Set ctx.setShouldReportUnloggedExceptions(false) to ignore known exceptions they don't need to be logged.

Result:

You no longer see warnings about ignorable exceptions.