Allow to specify target cluster architecture for tests

[barthy1]

Changes

When e2e or examples tests are started, hardware architectutere of the host
is always used. However test cases can be exectuted on cluster with another architecture,
using --kubeconfig parameter.
TEST_RUNTIME_ARCH allows to specify target cluster architecture to be able to use
correct restrictions and modifications, specific to concrete arch.

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Release Notes

Add TEST_RUNTIME_ARCH environment variable to specify target architecture of the tests

[tekton-robot]

Hi @barthy1. Thanks for your PR.

I'm waiting for a tektoncd member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[vdemeester]

/ok-to-test

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
test/multiarch_utils.go	58.8%	61.9%	3.1

[tekton-robot]

The following is the coverage report on the affected files.
Say /test pull-tekton-pipeline-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
test/multiarch_utils.go	58.8%	61.9%	3.1

[dlorenc]

/kind misc

[vdemeester]

/lgtm

[dlorenc]

/approve

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dlorenc

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