[ET-VK][conv1d] Route conv1d to height-packed implementations in export pipeline

[SS-JIA]

Stack from ghstack (oldest at bottom):

• [ET-VK][CI] Add test-vulkan-genai job for Parakeet on NVIDIA GPU runner #18335
• -> [ET-VK][conv1d] Route conv1d to height-packed implementations in export pipeline #18334
• [ET-VK][conv1d] Implement height-packed depthwise conv1d operator #18333
• [ET-VK][conv1d] Implement height-packed pointwise conv1d operator #18332

Integrate the new height-packed conv1d_pw and conv1d_dw operators into the
aten.convolution.default dispatch path so they are automatically used during
model export.

In op_registry.py, add a pick_conv_storage function that inspects the
convolution node at partition time. For 1D convolutions where the op is
pointwise (kernel_size=1) or depthwise (groups=C_in) and channels are 4-aligned,
it selects HEIGHT_PACKED_TEXTURE for input/output instead of the default
CHANNELS_PACKED_TEXTURE. All other cases (conv2d, grouped conv1d with K>1,
unaligned channels) retain channels-packed behavior.

In Convolution.cpp, add a height-packed routing block at the top of the conv1d
path. When the input tensor is height-packed, it dispatches to
et_vk.conv1d_pw.default or et_vk.conv1d_dw.default via VK_GET_OP_FN. Falls
through to the existing channels-packed add_conv1d_node path otherwise.

Differential Revision: D97344090

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/18334

• 📄 Preview Python docs built from this PR

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

✅ You can merge normally! (2 Unrelated Failures)

As of commit cc8a798 with merge base 9076110 ():

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

• pull / unittest / windows / windows-job (gh) (matched win rule in flaky-rules.json)
  ##[error]The operation was canceled.

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 / windows / windows-job (gh) (trunk failure)

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

[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.