`before_rename` Hook Fires Twice When Rename Is Enqueued

Description of the issue

When update_document_title is called with enqueue=True and the scheduler is active, the before_rename controller hook is called twice:

1. Once inside update_document_title itself — to get the transformed name for pre-validation before queuing
2. Again inside rename_doc when the background job executes — because rename_doc calls old_doc.run_method("before_rename", ...) with validate=True (the default)

Any before_rename implementation with side effects — sending emails, writing to external services, updating related records — will execute twice.

Context information (for bug reports)

Output of bench version

frappe 15.x.x (or develop branch)

Steps to reproduce the issue

1. Create a DocType with a custom before_rename hook that has a visible side effect (e.g. creates a log entry, sends an email, increments a counter)
2. Call update_document_title with enqueue=True on a document of that DocType
3. Wait for the background job to complete
4. Check how many times the side effect occurred

Observed result

before_rename side effect occurs twice — once immediately and once after the background job completes.

Expected result

before_rename should fire exactly once per rename operation.

Stacktrace / full error message

No exception — this is a silent double-execution bug.

Additional information

Call chain when enqueue=True:

update_document_title
  └── doc.run_method("before_rename", ...)        ← 1st call
  └── validate_rename(..., save_point=True)
  └── doc.queue_action("rename", ...)
        └── [background] execute_action
              └── doc.rename()
                    └── rename_doc(validate=True)
                          └── old_doc.run_method("before_rename", ...)  ← 2nd call

Fix — skip validation (and therefore before_rename) in the background job since it already ran synchronously before queuing:

# In update_docu