Add missing actions/stale permission

[opentelemetrybot]

Check if any workflow jobs are using actions/stale.

If so, make sure that the permissions block for that job contains

actions: write

If any of the other permissions lines have trailing comments, then add a trailing comment for this one too:

actions: write # because actions/stale deletes its old cache before saving new one

Place this new permission in a specific order within the permissions, directly before both:

issues: write
pull-requests: write

(which implicitly means after contents: read)