Say why the caller grants the permissions [ignore_release]

[snake14]

Description

The comment above the caller's permissions: block said they are granted "here and not in the called workflow". That is not true — plugin-branch-sweep.yml declares the same two scopes itself. The load-bearing fact is that its declaration can only cap them, never supply them, so the caller's grant is what makes the dispatch authorised; a reader who followed the comment to the callee found the opposite of what it promised.

Caught by a reviewer on the copy of this file added to innocraft/plugin-UsersFlow#138, where it is already corrected. Fixing it here too because this is the file the remaining plugin repositories will be copied from.

Comment-only: the two trailing per-scope comments also go, since they restated what the called workflow already documents.

Issue No

No GitHub issue.

Steps to Replicate the Issue

1. Read the comment above permissions: in .github/workflows/weekly-branch-sweep.yml.
2. Expected result: the called workflow does not declare these permissions, which is why the caller must.
3. Actual result: it does declare them, at the top of plugin-branch-sweep.yml.

Checklist

• [NA] Tested locally or on demo2/demo3?
• [NA] New test case added/updated?
• [NA] Are all newly added texts included via translation?
• [NA] Are text sanitized properly? (Eg use of v-text v/s v-html for vue)
• [NA] Version bumped?
• [✔] I have understood, reviewed, and tested all AI outputs before use
• [✔] All AI instructions respect security, IP, and privacy rules
• [NA] Documentation updated?