[11.x] Replaced array_push with direct array syntax

[xurshudyan]

According to PHP documentation, using $array[] = to add a single element is preferred over array_push() due to reduced overhead from function calls.

[FeBe95]

@xurshudyan Maybe all other occurrences of array_push() should be replaced as well? A quick search revealed only 6 other files that still contain array_push().