[test] Verify auto-assign bot silent-rejection fix (#649)

[Eeshu-Yadav]

Test issue for verifying openwisp/openwisp-utils#652, which fixes #649 (auto-assign bot claiming success on silent rejection).

Expected behaviour

When a non-collaborator opens a PR that says Fixes #<this-issue>:

1. The bot should not post the old "This issue has been automatically assigned to @user 🎯" comment.
2. The bot should post the fallback message telling the contributor to comment @openwisp-companion assign on this issue.
3. After the contributor comments @openwisp-companion assign, the bot should successfully assign them and post a confirmation.

Test steps

• Open a PR from a non-org account that references this issue with Fixes #<this-issue-number>
• Verify the bot posts the fallback message (not the false "assigned" claim)
• Comment @openwisp-companion assign on this issue from that non-org account
• Verify the bot actually assigns you and posts the success confirmation

This is purely a test issue — no real change is required. Close after testing is done.

[openwisp-companion]

Welcome back, @simplest-ayush! 🎉 This issue has been reassigned to you as you've reopened PR #98.

[openwisp-companion]

Hi @simplest-ayush 👋,

Thank you for opening PR #98 to address this issue!

GitHub did not allow the bot to assign this issue to you automatically, because you are not yet an organization member and have not previously commented on this issue.

To get assigned, please comment @openwisp-companion assign on this issue. Your comment satisfies GitHub's requirement and the bot will then assign the issue to you.

[simplest-ayush]

@openwisp-companion assign

[openwisp-companion]

This issue has been assigned to @simplest-ayush who opened PR #98 to address it. 🎯