Skip pfcwd_all_port_storm test on Arista-7060X6-64PE-256x200G

[Janetxxx]

Description of PR

Summary: Skip pfcwd/test_pfcwd_all_port_storm.py test on Arista-7060X6-64PE-256x200G, the pfc generation function on the Arista fanout device need to be improved by Arista.
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 202012
• 202205
• 202305
• 202311
• 202405

Approach

What is the motivation for this PR?

Currently, the test uses the python script to send the PFC frames, but the performance does not meet the requirements, and sometimes fails to trigger the PFC storm immediately. Slow pfc generation rate on 7060x6 200Gb.

How did you do it?

To address this, waiting for Arista to to improve the pfc generation function on the Arista fanout device. It would be better to use an Asic based pfc generation function.

How did you verify/test it?

======================================================================================== short test summary info =========================================================================================
SKIPPED [1] pfcwd/test_pfcwd_all_port_storm.py: Slow pfc generation rate on 7060x6 200Gb, pfc generation function on the Arista fanout device need to be improved by Arista
===================================================================================== 1 skipped, 1 warning in 29.87s =====================================================================================

Any platform specific information?

str3-7060x6-64pe-1

Supported testbed topology if it's a new test case?

t0-standalone-32

Documentation

[yutongzhang-microsoft]

LGTM

[Janetxxx]

@wangxin Could you please help to merge this PR, thanks

[mssonicbld]

Cherry-pick PR to 202405: #15902

[mssonicbld]

Cherry-pick PR to 202311: #15903