fix: allow selective override of keys in inputs field in the workfl…

…ow file when using `setInput` (#64)

Co-authored-by: Sam Peddamatham <sam.pm@infomagnus.com>

src/action-input/action-input.ts

@@ -17,11 +17,15 @@ export class ActionInput {
   toActArguments() {
     if (Object.keys(this.event.event).length > 0) {
       const eventCopy = { ...this.event.event };
-      eventCopy.inputs = Object.fromEntries(this.input.map);
+      // Merge inputs with existing event entries
+      eventCopy.inputs = { 
+        ...(eventCopy.inputs || {}), 
+        ...Object.fromEntries(this.input.map) 
+      };
       this.event.event = eventCopy;
       return [];
     } else {
       return this.input.toActArguments();
     }
   }
-}
+}