Remove process-based integration tests

[shreyas-s-rao]

How to categorize this issue?

/area testing
/kind task

What would you like to be added:
Process-based integration tests located here are no longer needed since these have been replaced by e2e tests introduced by #722 and are successfully running in the prow environment.

Removing integration tests from the current concourse pipeline also allows us to switch to GHA introduced by #894.

• Do not run integration tests in CI pipeline (fixed by migrate CICD-Pipeline to GitHub-Actions #894)
• Remove integration test code from repo

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