Pass weights_only flag to EXIR deserialization

[CaptnJackSparrow]

Summary:
This is a workaround to the following error during deserialization of the EXIR graph:

Weights only load failed. This file can still be loaded, to do so you have two options, �[1mdo those steps only if you trust the source of the checkpoint�[0m.
	(1) In PyTorch 2.6, we changed the default value of the `weights_only` argument in `torch.load` from `False` to `True`. Re-running `torch.load` with `weights_only` set to `False` will likely succeed, but it can result in arbitrary code execution. Do it only if you got the file from a trusted source.
	(2) Alternatively, to load with `weights_only=True` please check the recommended steps in the following error message.
	WeightsUnpickler error: Unsupported global: GLOBAL executorch.exir.serde.export_serialize._reconstruct_fake_tensor was not an allowed global by default. Please use `torch.serialization.add_safe_globals([executorch.exir.serde.export_serialize._reconstruct_fake_tensor])` or the `torch.serialization.safe_globals([executorch.exir.serde.export_serialize._reconstruct_fake_tensor])` context manager to allowlist this global if you trust this class/function.

Differential Revision: D98258299

[pytorch-bot]

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❌ 2 New Failures, 2 Unrelated Failures

As of commit ec4d230 with merge base 02cb325 ():

NEW FAILURES - The following jobs have failed:

• Lint / lintrunner-mypy (gh)
  >>> Lint for backends/arm/test/models/stable_diffusion/stable_diffusion_module_test_configs.py:
• pull / test-voxtral-realtime-xnnpack-linux / linux-job (gh)
  RuntimeError: Command docker exec -t 1be0ec1d85cd2d9a253970923258a4a984765016aa05fcf80fbab361276fcc06 /exec failed with exit code 1

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / windows / windows-job (gh) (trunk failure)
  ##[error]The operation was canceled.
• pull / unittest-editable / windows / windows-job (gh) (trunk failure)

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@CaptnJackSparrow has exported this pull request. If you are a Meta employee, you can view the originating Diff in D98258299.

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