fix: validate header against parent in engine2 (#10114)

Co-authored-by: Matthias Seitz <matthias.seitz@outlook.de>

crates/chain-state/src/test_utils.rs

@@ -138,6 +138,8 @@ impl TestBlockBuilder {
                     EMPTY_ROOT_HASH,
                 ),
             )])),
+            // use the number as the timestamp so it is monotonically increasing
+            timestamp: number,
             ..Default::default()
         };