[CI][Rebase]: run full e2e suite in rebase Ready/Merge pipelines in the rebase pipeline[skip-ci] (#4478)

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

.buildkite/rebase-pipeline.yaml

@@ -14,7 +14,7 @@ steps:
     depends_on: image-build
     key: upload-ready-pipeline
     commands:
-      - python3 .buildkite/scripts/upload_pipeline.py --upload .buildkite/test-ready.yml
+      - buildkite-agent pipeline upload .buildkite/test-ready.yml
     agents:
       queue: "cpu_queue_premerge"
 
@@ -23,7 +23,7 @@ steps:
     depends_on: image-build
     key: upload-merge-pipeline
     commands:
-      - python3 .buildkite/scripts/upload_pipeline.py --upload .buildkite/test-merge.yml
+      - buildkite-agent pipeline upload .buildkite/test-merge.yml
     agents:
       queue: "cpu_queue_premerge"