Remove un-used copy from building dockers

[Erik-Lundell]

The removed copy seems to be stale, it is never used.

cc @digantdesai @freddan80 @per @zingo @oscarandersson8218 @mansnils @Sebastian-Larsson @robell

[pytorch-bot]

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🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/18868

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❌ 3 New Failures, 10 Cancelled Jobs, 3 Unrelated Failures

As of commit afdacf2 with merge base 2eaa16c ():

NEW FAILURES - The following jobs have failed:

• trunk / test-torchao-huggingface-checkpoints (lfm2_5_1_2b, linux.arm64.2xlarge, executorch-ubuntu-22.04-g... / linux-job (gh)
  RuntimeError: Command docker exec -t 98dca26b7f065c471e8373da8d19339ddc1e97e8cd0bfe1760d19ff789e20eda /exec failed with exit code 1
• trunk / test-torchao-huggingface-checkpoints (phi_4_mini, linux.arm64.2xlarge, executorch-ubuntu-22.04-gc... / linux-job (gh)
  RuntimeError: Command docker exec -t c3c7806d5ea13b102309188b2f4b68c77a71e17885c4fcabbd1e7cf61f442e8e /exec failed with exit code 1
• trunk / test-torchao-huggingface-checkpoints (qwen3_4b, linux.arm64.2xlarge, executorch-ubuntu-22.04-gcc1... / linux-job (gh)
  RuntimeError: Command docker exec -t 92c838a6a3a50678878d3eab76129f95e13f1b9dfdcd5b497275a2b8ef5929cd /exec failed with exit code 1

CANCELLED JOBS - The following jobs were cancelled. Please retry:

• pull / test-multimodal-linux (gemma3-4b) / linux-job (gh)
  ##[error]The operation was canceled.
• pull / unittest / linux / linux-job (gh)
  ##[error]The operation was canceled.
• pull / unittest-editable / linux / linux-job (gh)
  ##[error]The operation was canceled.
• trunk / test-demo-backend-delegation (buck2) / linux-job (gh)
  ##[error]The operation was canceled.
• trunk / test-demo-backend-delegation (cmake) / linux-job (gh)
• trunk / test-llama-runner-mac (fp32, xnnpack+custom+quantize_kv) / macos-job (gh)
  ##[error]The operation was canceled.
• trunk / test-models-linux-aarch64 (ic4, portable, linux.arm64.2xlarge) / linux-job (gh)
  ##[error]The operation was canceled.
• trunk / test-models-linux-aarch64 (phi_4_mini, portable, linux.arm64.m7g.4xlarge) / linux-job (gh)
  ##[error]The operation was canceled.
• trunk / test-models-macos-coreml (vit) / macos-job (gh)
  ##[error]The operation was canceled.
• trunk / unittest-release / linux / linux-job (gh)
  ##[error]The operation was canceled.

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

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

[digantdesai]

IIUC, and this was a while ago, this was needed to make sure we get the latest files in the docker build for the PR we are testing.

[Erik-Lundell]

You might be right, but I am not able to find any evidence of this being used. If you look at the PR that introduced it, https://github.com/pytorch/executorch/pull/1111/changes, ./arm is copied to the docker's /opt/arm to then run setup.sh. This code does not exist anymore. The only thing the ARM_SDK arg does is run install_arm.sh, which just installs some drivers.

[zingo]

Now when all deps a pip packages (even tosa-tools and MLSDK) we can and probably should clean out all stuff from the docker and use a plain one.
As a later improvements we can just prerun some pip installs to speed things up if we want.
e.g. I propose to merge this, cleanup old strange stuff and then maybe rethink the docker acceleration setup so we get a clean one. Would that be ok @digantdesai ?