Arm backend: Add 6D tensor and pixel shuffle/unshuffle support

[pytorchbot]

Adds 6D tensor support required by pixel_shuffle/pixel_unshuffle when given 4D inputs, which means for now we only support 4D inputs. Adds TOSA, VGF and xfailing Ethos-U85 unit tests.

cc @digantdesai @freddan80 @per @zingo @oscarandersson8218

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/14854

• 📄 Preview Python docs built from this PR

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

❌ 5 New Failures, 2 Cancelled Jobs

As of commit 5d656a8 with merge base e0dda90 ():

NEW FAILURES - The following jobs have failed:

• Build Presets / apple (ios) / build (gh)
• Lint / lintrunner / linux-job (gh)
  >>> Lint for backends/arm/_passes/to_tosa_memory_format_pass.py:
• Lint / lintrunner-mypy / linux-job (gh)
  >>> Lint for backends/arm/_passes/to_tosa_memory_format_pass.py:
• pull / unittest-arm-backend-with-no-fvp (test_pytest_models) / linux-job (gh)
  RuntimeError: Command docker exec -t 784abd442013a014c0955eba8dfb88b032bfd9e25ae3f1f94f3a55030a45af7f /exec failed with exit code 1
• pull / unittest-arm-backend-with-no-fvp (test_pytest_ops) / linux-job (gh)
  RuntimeError: Command docker exec -t b25228d9a45142a45b90ec3753922599c7dafb54ffac66dbca3ecd347d329896 /exec failed with exit code 1

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

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

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

[GregoryComer]

@digantdesai It looks like there are some issues with the cherry-pick. Can you help fix the PR? It will likely need a maintainer to push changes to the PR branch, so I don't think the ARM engineers can do it. Thanks.