go: add «2425. Bitwise XOR of All Pairings»

URL:	https://leetcode.com/problems/bitwise-xor-of-all-pairings/
Signed-off-by: Matej Focko <me@mfocko.xyz>

go/bitwise-xor-of-all-pairings.go

@@ -0,0 +1,19 @@
+package main
+
+func xorAllNums(nums1 []int, nums2 []int) int {
+	xorFold := func(nums []int, otherLength int) int {
+		acc := 0
+		if otherLength%2 == 0 {
+			return acc
+		}
+
+		for _, num := range nums {
+			acc ^= num
+		}
+
+		return acc
+	}
+
+	xor1, xor2 := xorFold(nums1, len(nums2)), xorFold(nums2, len(nums1))
+	return xor1 ^ xor2
+}