arrays: fix examples for find_first and find_last (#19153)

Author: ttytm

vlib/arrays/arrays.v

@@ -681,7 +681,7 @@ pub fn carray_to_varray[T](c_array_data voidptr, items int) []T {
 
 // find_first returns the first element that matches the given predicate
 // returns `none`, if there is no match found
-// Example: arrays.find_first([1, 2, 3, 4, 5], fn (arr int) bool { arr == 3}) // => 3
+// Example: arrays.find_first([1, 2, 3, 4, 5], fn (i int) bool { return i == 3 })? // => 3
 pub fn find_first[T](array []T, predicate fn (elem T) bool) ?T {
 	if array.len == 0 {
 		return none
@@ -696,7 +696,7 @@ pub fn find_first[T](array []T, predicate fn (elem T) bool) ?T {
 
 // find_last returns the last element that matches the given predicate
 // returns `none`, if there is no match found
-// Example: arrays.find_last([1, 2, 3, 4, 5], fn (arr int) bool { arr == 3}) // => 3
+// Example: arrays.find_last([1, 2, 3, 4, 5], fn (i int) bool { return i == 3})? // => 3
 pub fn find_last[T](array []T, predicate fn (elem T) bool) ?T {
 	if array.len == 0 {
 		return none