[WIP] Fix fallback issue creation route for safe output

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

Original prompt

Reference: https://github.com/github/gh-aw/actions/runs/21689598271/job/62546849702#step:6:1

@copilot the fallback issue creation route for the create-discussion safe output requires the issue: write permission in the safe output job.

Also make sure that the discussions: write permission is set.

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