Hygiene: removed unused images package variable.

[bendory]

Changes

Deleted unused package-level variable in unit test.

Submitter Checklist

As the author of this PR, please check off the items in this checklist:

• [N/A] Has Docs included if any changes are user facing
• Has Tests included if any functionality added or changed
• Follows the commit message standard
• Meets the Tekton contributor standards (including
  functionality, content, code)
• Has a kind label. You can add one by adding a comment on this PR that contains /kind <type>. Valid types are bug, cleanup, design, documentation, feature, flake, misc, question, tep
• [N/A] Release notes block below has been updated with any user facing changes (API changes, bug fixes, changes requiring upgrade notices or deprecation warnings)
• [N/A] Release notes contains the string "action required" if the change requires additional action from users switching to the new release

/kind cleanup

Release Notes

NONE

[tekton-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lbernick

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [lbernick]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[dibyom]

/lgtm