perf(array): avoid double bounds check in ArrayIterator (risingwavelabs#8685)

Signed-off-by: TennyZhuang <[email protected]>

Author: TennyZhuang

src/common/src/array/iterator.rs

@@ -34,7 +34,8 @@ impl<'a, A: Array> Iterator for ArrayIterator<'a, A> {
         if self.pos >= self.data.len() {
             None
         } else {
-            let item = self.data.value_at(self.pos);
+            // SAFETY: bounds check is done by `self.pos < self.data.len()`.
+            let item = unsafe { self.data.value_at_unchecked(self.pos) };
             self.pos += 1;
             Some(item)
         }