Remove internal executorch dependency on torchao.quantization.subclass

[andrewor14]

Summary:
Summary: This is a really old quantization API that we
recently removed in torchao (D84842047). No one should be
calling it anymore. For BC, let's just copy the base class
into executorch for now. We should delete this in the future.

Test Plan: CI

Differential Revision: D84921134

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/15223

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 8 New Failures, 2 Unrelated Failures

As of commit 01e01b0 with merge base 5076749 ():

NEW FAILURES - The following jobs have failed:

• pull / test-samsung-models-linux / linux-job (gh)
  RuntimeError: Command docker exec -t f7ef8f39e2e7398ff6f8489643f6a57544cab2a8b145e50cba42ff8a06a6e103 /exec failed with exit code 1
• pull / unittest-nxp-neutron / linux-job (gh)
  RuntimeError: Command docker exec -t 43d2eef12943cb73a67daa7b315daed163cd1506a1cfebaef12f9f084f5e6032 /exec failed with exit code 1
• Test CUDA Builds / export-gemma3-cuda-non-quantized / linux-job (gh)
  RuntimeError: Command docker exec -t c657909bbb648af4ff18d2b5cf67aebaabaa06719bcf4ddac473436c1af1ea03 /exec failed with exit code 2
• Test CUDA Builds / export-gemma3-cuda-quantized-int4-tile-packed / linux-job (gh)
  RuntimeError: Command docker exec -t 0caba69823b3c363decbb078db20e5230129e42d493b604a58cf37c130f99126 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-non-quantized / linux-job (gh)
  RuntimeError: Command docker exec -t 17e171d02e6ac2ed66d1d4152fc22d16125187e9fb9fab314a3888c562112763 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-quantized-int4-tile-packed / linux-job (gh)
  RuntimeError: Command docker exec -t d9b6fda7085a2933feb19172a0ac8b9a1459e86ab956a636269cf4a92d31eb4b /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-quantized-int4-weight-only / linux-job (gh)
  RuntimeError: Command docker exec -t 28b80f33ecd0c0704ce6617cde85670737500965f9ddba98d73352f2146cf39c /exec failed with exit code 2
• Test Metal Backend / export-voxtral-metal-artifact / macos-job (gh)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 2

FLAKY - The following job failed but was likely due to flakiness present on trunk:

• pull / unittest / linux / linux-job (gh) (detected as infra flaky with no log or failing log classifier)

BROKEN TRUNK - The following job failed but was present on the merge base:

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

• pull / unittest-editable / linux / linux-job (gh) (trunk failure)

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[meta-codesync]

@andrewor14 has exported this pull request. If you are a Meta employee, you can view the originating Diff in D84921134.

[github-actions]

This PR needs a release notes: label

If your change should be included in the release notes (i.e. would users of this library care about this change?), please use a label starting with release notes:. This helps us keep track and include your important work in the next release notes.

To add a label, you can comment to pytorchbot, for example
@pytorchbot label "release notes: none"

For more information, see
https://github.com/pytorch/pytorch/wiki/PyTorch-AutoLabel-Bot#why-categorize-for-release-notes-and-how-does-it-work.

[andrewor14]

@larryliu0820

[lucylq]

Can we tag this as deprecated?

from executorch.exir._warnings import deprecated
.. 
@deprecated("QuantizedLinearWeightBase is deleted from torchao ... ")
class QuantizedLinearWeightBase(torch.Tensor):