Plumb the "TEKTON_RESOURCE_NAME" env var into the cluster and PR reso…

[dlorenc]

…urces.

Changes

As part of TEP-0025 (hermetic builds), we need to know which containers/steps are part
of the "Tekton system" and which ones are part of the Task definition. This PR adds
the TEKTON_RESOURCE_NAME environment variable to the injected copy containers.

This variable is already used by several of the existing resources (git, image).

/kind feature

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
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• [ X] Includes tests (if functionality changed/added)
• Includes docs (if user facing)
• Commit messages follow commit message best practices
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• If you are adding a new binary/image to the cmd dir, please update
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Reviewer Notes

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Release Notes

The TEKTON_RESOURCE_NAME environment variable is now set on the injected PR and cluster resource containers.

[bobcatfish]

/approve
/lgtm

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bobcatfish

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