[CodeQuality] Deprecate ForeachItemsAssignToEmptyArrayToAssignRector

[TomasVotruba]

Deprecate ForeachItemsAssignToEmptyArrayToAssignRector.

The foreach-append and the direct array assign are not equivalent. The foreach re-indexes keys from 0, while the direct assign keeps the original keys:

$items = [3 => 'a', 7 => 'b'];
// loop:       [0 => 'a', 1 => 'b']
// assignment: [3 => 'a', 7 => 'b']

This can create risky situations with sparse arrays, so the rule is deprecated.