fix type

Author: icecrasher321

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts

@@ -549,7 +549,7 @@ export function useWorkflowExecution() {
     })
 
     // Merge subblock states from the appropriate store (scoped to active workflow)
-    const mergedStates = mergeSubblockState(validBlocks, activeWorkflowId)
+    const mergedStates = mergeSubblockState(validBlocks, activeWorkflowId ?? undefined)
 
     // Debug: Check for blocks with undefined types after merging
     Object.entries(mergedStates).forEach(([blockId, block]) => {