[CI] change ds32 cudagraph_sizes

[starmountain1997]

What this PR does / why we need it?

This PR fixes the single-node nightly test for DeepSeek V3.2 (W8A8) model to ensure CI stability. The changes include:

1. Simplified nightly test matrix (nightly_test_a3.yaml):
   • Temporarily reduced to only run deepseek3_2-w8a8 test case for debugging
   • Changed trigger from schedule/workflow_dispatch to support push/pull_request for faster iteration
2. Updated DeepSeek V3.2 test configuration (test_deepseek_v3_2_w8a8.py):
   • Adjusted cudagraph_capture_sizes from [3, 6, 9, 12] to [8, 16, 24, 32] for better performance
   • Increased max-num-seqs from 4 to 8
   • Increased gpu-memory-utilization from 0.92 to 0.98
   • Increased num_speculative_tokens from 2 to 3
3. Added PR checkout step (_e2e_nightly_single_node.yaml):
   • Added ability to checkout a specific PR ([CI] change ds32 cudagraph_sizes #6399) for testing

Does this PR introduce any user-facing change?

No. This PR only affects CI/CD test configurations and does not introduce any user-facing changes.

How was this patch tested?

The nightly test workflow will run the DeepSeek V3.2 W8A8 test case with the updated configuration to verify the changes work correctly.

[gemini-code-assist]

Code Review

This pull request updates the E2E test configuration for the deepseek_v3_2_w8a8 model. The changes include increasing max-num-seqs, adjusting gpu-memory-utilization, updating cudagraph_capture_sizes to align with the new sequence count, and enabling layer sharding for memory optimization. These adjustments appear to be for performance tuning of the test. My review includes one suggestion to remove a commented-out line to improve code clarity.

[gemini-code-assist]

This commented-out line appears to be a remnant of testing or debugging. Leaving commented-out code can lead to confusion for future maintainers, who might not know its purpose or whether it should be restored. To improve code clarity and maintainability, it's best to remove this line. If this configuration is important, it should be documented elsewhere or managed through a more explicit configuration mechanism.

[github-actions]

This pull request has conflicts, please resolve those before we can evaluate the pull request.

[wangxiyuan]

please fix the lint error

[starmountain1997]

please fix the lint error

fixed