Warning: Undefined array key "context_visibility" in layout_builder_context_form_alter()

This fix still throws the error for us.
This PHP 8.2 null coalescing operator basic example throws same error.
We should use isset() to check the key exists.

$a = ['key' => 'value'];
$b = (is_array($a['not_a_key'])) ? $a : [];
print_r($b);

Warning: Undefined array key "not_a_key"