[CI] Flaky kvmtest-t1-lag-vpp failures on unrelated PRs

[rustiqly]

Description

The kvmtest-t1-lag-vpp Elastictest CI check (marked [OPTIONAL]) is failing intermittently on PRs that do not modify any VPP-related code.

Affected PRs (examples)

• [vs] Enable SAI_VS_USE_CONFIGURED_SPEED_AS_OPER_SPEED in VS platform sai.profile #25428 (VS sai.profile oper speed flag)
• [cfggen] Fix invalid broadcast address for /31 and /32 mgmt subnets #25442 (cfggen /31 broadcast None fix)

CI Links

• Build 1046317: https://dev.azure.com/mssonic/be1b070f-be15-4154-aade-b1d3bfb17054/_build/results?buildId=1046317
• Build 1046319: https://dev.azure.com/mssonic/be1b070f-be15-4154-aade-b1d3bfb17054/_build/results?buildId=1046319

Note

This check is marked OPTIONAL but still shows as a failure in the PR status, which can confuse reviewers and contributors.

Impact

Creates noise in PR CI status and wastes time investigating.