Collection throws error: "Can only flip string and integer values, entry skipped"

[martio]

Laravel Version

10.11.0

PHP Version

8.2.4

Database Driver & Version

No response

Description

Collection throws error: "Can only flip string and integer values, entry skipped":

        "message": "array_flip(): Can only flip string and integer values, entry skipped",
        "file": "/var/www/html/vendor/laravel/framework/src/Illuminate/Collections/Collection.php",
        "line": 421

Steps To Reproduce

Sorting data...

[cosmastech]

collect(['a' => []])->flip();

would be creating an array like:

$myArray = [
    [] => 'a'
];

But this returns a TypeError as arrays only accept strings & ints as their keys (to my knowledge).