Fix flaky tests and make builds deterministic

[kostis-codefresh]

Summary

There are several E2E tests that break all the time. This makes contributor work very difficult.

Use Cases

Examples of commits with failed tests

https://github.com/argoproj/argo-rollouts/actions/runs/14712277237/job/41287384542
https://github.com/argoproj/argo-rollouts/actions/runs/13277626443/job/37069985746
https://github.com/argoproj/argo-rollouts/actions/runs/14755408824/job/41422279926

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