[5.5] Prevent accessing object properties using array access

[mrliptontea]

Previous PR: #18391

This time I decided not to introduce any new methods, just make array access behave exactly as magic methods do.

Note: I still think this is a bug fix, and according to the documentation, it should go into latest or LTS.

[mrliptontea]

Potential refactor, for consistency: Illuminate\Container\Container is re-using offset methods implicitly.
Either I change it in my PR so Model and Fluent do the same, or change Container to call offset methods.