Use PTEFile class in serialize_pte_binary

[lucylq]

manual merge to main of: #15801

from branch gh/lucylq/126/base

[pytorch-bot]

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❌ 3 New Failures, 75 Pending

As of commit 6bd67b1 with merge base 584d39b ():

NEW FAILURES - The following jobs have failed:

• pull / test-llama-runner-qnn-linux (fp32, qnn_8a8w, qnn) / linux-job (gh)
  RuntimeError: Command docker exec -t 923eebedde828325f95ece6995ff5780d84f9babc8c5e8adc3631ddf06da3aa0 /exec failed with exit code 1
• pull / test-models-linux (resnet18, xnnpack-quantization-delegation, linux.2xlarge) / linux-job (gh)
  RuntimeError: Command docker exec -t 741717adf99457736a3aae567a9682fa26ff1325df8f9e4c8c57893e4ce92956 /exec failed with exit code 1
• pull / test-multimodal-linux (gemma3-4b) / linux-job (gh)
  RuntimeError: Command docker exec -t ec41afbb10d28684f4de2f05c69d414ad0de57c366b308a9985f35433f0b5505 /exec failed with exit code 1

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