Imported slack bots can have been made with invalid email addresses

[alexmv]

Prior to b945aa3443110cac98736ba33c32ff5899e0b237, we used make a Slack bot's email address via its real_name_normalized or first_name field, stripping out spaces and the "Bot" string, and putting an @zulip.whatever.com on the end. This could make email addresses which were invalid, causing errors on import if the realm was exported and imported.

We should add a migration to fix invalid email addresses from before b945aa3443110cac98736ba33c32ff5899e0b237. This likely involves looking for bots whose email is -bot@, validating them using an email validator, and re-quoting them as necessary to make them validate.

Zulip Server and web app version:

• [ ] Zulip Cloud (*.zulipchat.com)
• [ ] Zulip Server 7.0+
• [ ] Zulip Server 6.0+
• [ ] Zulip Server 5.0 or older
• [ ] Other or not sure

[zulipbot]

Hello @zulip/server-bots, @zulip/server-misc, @zulip/server-production members, this issue was labeled with the "area: production", "area: db cleanup", "area: export/import", "area: bots" labels, so you may want to check it out!

[Sanket-0510]

@zulipbot claim

[zulipbot]

Hello @Sanket-0510!

Thanks for your interest in Zulip! You have attempted to claim an issue without the label "help wanted". You can only claim and submit pull requests for issues with the help wanted label.

If this is your first time here, we recommend reading our guide for new contributors before getting started.