Remove duplicate edit-form key in Drupal\aggregator\Entity\Feed

This issue has novice tasks. If you are an experienced core developer and have multiple commit mentions, please review novices' work on these tasks rather than doing them yourself. Feedback from experienced contributors is valued.

Problem/Motivation

 *   links = {
 *     "canonical" = "aggregator.feed_view",
 *     "edit-form" = "aggregator.feed_configure",
 *     "delete-form" = "aggregator.feed_delete",
 *     "edit-form" = "aggregator.feed_configure",
 *   },

edit-form is duplicated.

Proposed resolution

Remove line of code.

Remaining tasks

• Write patch (novice)
• Review patch to check it fixes the issue, the change is properly documented and for coding standards. Provide test evidence (novice)
• Keep issue summary up to date (novice)

User interface changes

None

API changes

None