Fix AttributeError in onnxruntime train_unconditional

The ORT example `examples/research_projects/onnxruntime/unconditional_image_generation/train_unconditional.py`
defines `--logger` (argparse line 196) but references `args.report_to`
in two places:

  * Line 280: `if args.report_to == "wandb" and args.hub_token is not None:`
  * Line 294: `log_with=args.report_to,`

Since there is no `--report_to` flag on the parser, both references crash
with `AttributeError: 'Namespace' object has no attribute 'report_to'`
as soon as `main()` starts — the script cannot run at all.

The sibling non-ORT script
`examples/unconditional_image_generation/train_unconditional.py` uses
`args.logger` consistently; this PR aligns the ORT variant with that
behavior, and updates the error message to refer to `--logger=wandb`
instead of the non-existent `--report_to=wandb`.

Author: Ricardo-M-L

examples/research_projects/onnxruntime/unconditional_image_generation/train_unconditional.py

@@ -277,9 +277,9 @@ def parse_args():
 
 
 def main(args):
-    if args.report_to == "wandb" and args.hub_token is not None:
+    if args.logger == "wandb" and args.hub_token is not None:
         raise ValueError(
-            "You cannot use both --report_to=wandb and --hub_token due to a security risk of exposing your token."
+            "You cannot use both --logger=wandb and --hub_token due to a security risk of exposing your token."
             " Please use `hf auth login` to authenticate with the Hub."
         )
 
@@ -291,7 +291,7 @@ def main(args):
     accelerator = Accelerator(
         gradient_accumulation_steps=args.gradient_accumulation_steps,
         mixed_precision=args.mixed_precision,
-        log_with=args.report_to,
+        log_with=args.logger,
         project_config=accelerator_project_config,
     )