refactor(bytes): prepare for noUncheckedIndexedAccess (#4119)

refactor(bytes): prepare for noUncheckedIndexedAccess

bytes/equals_test.ts

@@ -19,7 +19,7 @@ Deno.test("equals() handles randomized testing", () => {
     const arr3 = arr1.slice(0);
     // the chance of arr1 equaling arr2 is basically 0
     // but introduce an inequality at the end just in case
-    arr2[arr2.length - 1] = arr1[arr1.length - 1] ^ 1;
+    arr2[arr2.length - 1] = arr1.at(-1)! ^ 1;
     // arr3 is arr1 but with an inequality in the very last element
     // this is to test the equality check when length isn't a multiple of 4
     arr3[arr3.length - 1] ^= 1;