fix(workflows): allow github CDN egress in recompile-safe-output-fixtures (#864)

GitHub release downloads redirect to release-assets.githubusercontent.com,

which is covered by the `github` ecosystem identifier but not by `defaults`.

Without it, AWF blocks the curl in Step 2 and the workflow loops through its

12 retry attempts then aborts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jamesadevine