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

src/server/game/Handlers/LFGHandler.cpp

@@ -373,7 +373,7 @@ void WorldSession::SendLfgUpdateParty(lfg::LfgUpdateData const& updateData)
     {
         case lfg::LFG_UPDATETYPE_ADDED_TO_QUEUE:                // Rolecheck Success
             queued = true;
-            // no break on purpose
+            [[fallthrough]];
         case lfg::LFG_UPDATETYPE_PROPOSAL_BEGIN:
             join = true;
             break;