feat: ignore robots when accessing magic link

[michalsn]

Description
This PR updates the magic link controller to ignore requests originating from bots or crawlers.

See #1293 for more details.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[datamweb]

@michalsn, thank you. I know the main focus of the discussion has been on the magic link, but I remember someone mentioning a similar issue regarding the activation link as well.
I’d like to know what your plan is regarding that issue?

[lonnieezell]

Looks great, thanks!

[datamweb]

Since the list of bots was recently updated in CodeIgniter version 4.7, but Shield remains compatible with earlier versions, I think it would be helpful to mention in Shield’s documentation that the bot list can be updated through the app/Config/UserAgents.php file.

[michalsn]

@datamweb I have added the docs.

We can add the same functionality to all actions in a separate PR. I think the right place for that would be https://github.com/codeigniter4/shield/blob/develop/src/Controllers/ActionController.php#L83, right?

[datamweb]

https://github.com/codeigniter4/shield/blob/develop/src/Controllers/ActionController.php#L83, right?

Yes.

[datamweb]

LGTM, Thanks.

[michalsn]

Thank you for your review!