Fix exception caused by a log message (#8558) (#8701) (#8756)

Co-authored-by: peter-perot <peter-perot@users.noreply.github.com>

src/Orleans.Runtime/Silo/Silo.cs

@@ -612,7 +612,7 @@ await grainService
                     logger.LogDebug(
                         "{GrainServiceType} Grain Service with Id {GrainServiceId} stopped successfully.",
                         grainService.GetType().FullName,
-                        grainService.GetPrimaryKeyLong(out string ignored));
+                        grainService.GetGrainId().ToString());
                 }
             }
         }