fix: pal needs u8

Author: nhtyy

library/std/src/sys/pal/zkvm/mod.rs

@@ -62,11 +62,11 @@ pub fn abort_internal() -> ! {
 }
 
 pub fn hashmap_random_keys() -> (u64, u64) {
-    let mut buf = [0u32; 16];
+    let mut buf = [0u8; 16];
     unsafe {
         abi::sys_rand(buf.as_mut_ptr(), buf.len());
     };
     let a = u64::from_le_bytes(buf[0..8].try_into().unwrap());
     let b = u64::from_le_bytes(buf[8..16].try_into().unwrap());
     (a, b)
-}
+}