fix(Core/Misc): all GCC warnings (#3457)

src/server/game/DungeonFinding/LFGPlayerData.cpp

@@ -30,10 +30,10 @@ void LfgPlayerData::SetState(LfgState state)
             m_Roles = 0;
             m_SelectedDungeons.clear();
             m_Comment = "";
-            // No break on purpose
+            [[fallthrough]];
         case LFG_STATE_DUNGEON:
             m_OldState = state;
-            // No break on purpose
+            [[fallthrough]];
         default:
             m_State = state;
     }