[One workflow][Telemetry] input as jsonSchema (elastic#258515)

Input count was consistently reported as 0.
The extraction logic assumed the old array-like structure, but the input
is now always converted to JSON Schema.

Author: rosomri

src/platform/plugins/shared/workflows_execution_engine/server/lib/telemetry/utils/extract_workflow_metadata.ts

@@ -185,7 +185,7 @@ export function extractWorkflowMetadata(
   const hasAlertTriggers = triggers.some((trigger) => trigger?.type === 'alert');
 
   // Count inputs
-  const inputCount = Array.isArray(workflow.inputs) ? workflow.inputs.length : 0;
+  const inputCount = Object.keys(workflow.inputs?.properties ?? {}).length;
 
   // Extract settings
   const enabled = Boolean(workflow.enabled);