Mention relevant CR in an improved trigger_error() message in FormattableMarkup::placeholderFormat()

Attached patch against drupal 10.1.x

Tried to fix CCF on #30

fixed ccf #30
Please review it.

fixed ccf #30

The last submitted patch, 35: 2834359-35.patch, failed testing. View results →

The error message was changed in 🐛 Invalid placeholder error message should say what's wrong with it Fixed to the following, which is more helpful.

            // Warn for random placeholders that won't be replaced.
            trigger_error(sprintf('Placeholders must begin with one of the following "@", ":" or "%%", invalid placeholder (%s) with string: "%s"', $key, $string), E_USER_WARNING);
          }

I think the current message provides enough information to help someone fix the problem, making this a won't fix.