[ggrigory]

Adds two workflows that connect ni/vsomeip to the srd-tran-vehicle-networks AzDO pipelines:

• "trigger-azdo-pr-pipeline.yml" - on PRs targeting "ni/main" (skips drafts and fork PRs), queues the AzDO someip PR pipeline, waits for the result, and cancels the AzDO run when superseded or cancelled
• "trigger-azdo-revision-update.yml" - on push to "ni/main", queues the AzDO pipeline that updates "vsomeip-revision.txt". On success, that pipeline opens an auto-complete PR in srd-tran-vehicle-networks that updates "someip/vsomeip/vsomeip-revision.txt" to the new "ni/main" SHA. When that PR merges to "main", the AzDO someip CI pipeline triggers automatically, so it builds and tests the pinned revision right away.