feat(op-challenger): Parallelize Agent Actions (#9804)

* feat(op-challenger): Place agent actions behind a synced wait group

* op-challenger: Split out individual action into a separate method to reduce nesting.

---------
Co-authored-by: Adrian Sutton <adrian@oplabs.co>

op-challenger/game/fault/agent.go

@@ -67,19 +67,28 @@ func (a *Agent) Act(ctx context.Context) error {
 	if a.tryResolve(ctx) {
 		return nil
 	}
+
 	game, err := a.newGameFromContracts(ctx)
 	if err != nil {
 		return fmt.Errorf("create game from contracts: %w", err)
 	}
 
-	// Calculate the actions to take
 	actions, err := a.solver.CalculateNextActions(ctx, game)
 	if err != nil {
 		a.log.Error("Failed to calculate all required moves", "err", err)
 	}
 
-	// Perform the actions
+	var wg sync.WaitGroup
+	wg.Add(len(actions))
 	for _, action := range actions {
+		go a.performAction(ctx, &wg, action)
+	}
+	wg.Wait()
+	return nil
+}
+
+func (a *Agent) performAction(ctx context.Context, wg *sync.WaitGroup, action types.Action) {
+	defer wg.Done()
 	actionLog := a.log.New("action", action.Type, "is_attack", action.IsAttack, "parent", action.ParentIdx)
 	if action.Type == types.ActionTypeStep {
 		containsOracleData := action.OracleData != nil
@@ -108,8 +117,6 @@ func (a *Agent) Act(ctx context.Context) error {
 	if err != nil {
 		actionLog.Error("Action failed", "err", err)
 	}
-	}
-	return nil
 }
 
 // tryResolve resolves the game if it is in a winning state