Remove unnecessary try/catch from logger

Problem/Motivation

From #2986294: Remove $context['user'] from LoggerChannel::log.

      try {
        if ($this->currentUser) {
          $context['uid'] = $this->currentUser->id();
        }
      }
      catch (\Exception $e) {
        // An exception might be thrown if the database connection is not
        // available or due to another unexpected reason. It is more important
        // to log the error that we already have so any additional exceptions
        // are ignored.
      }

As far as I can see there is never a situation anymore when getting the ID from the current_user service can throw an exception. This was resolved in #2753733: AccountProxy can do unnecessary user loads to get an ID

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes