fix(create-story): replace missing validate-workflow invoke with explicit checklist action (#1837)

Co-authored-by: Brian <bmadcode@gmail.com>

Author: alexeyv

src/bmm/workflows/4-implementation/create-story/instructions.xml

@@ -311,7 +311,7 @@
   </step>
 
   <step n="6" goal="Update sprint status and finalize">
-    <invoke-task>Validate against checklist at {installed_path}/checklist.md using _bmad/core/tasks/validate-workflow.xml</invoke-task>
+    <action>Validate the newly created story file {story_file} against {installed_path}/checklist.md and apply any required fixes before finalizing</action>
     <action>Save story document unconditionally</action>
 
     <!-- Update sprint status -->