Revert "Also check hash value"

This reverts commit 50bfc7b.

datafusion/src/physical_plan/hash_aggregate.rs

@@ -365,13 +365,10 @@ fn group_aggregate_batch(
     for (row, hash) in batch_hashes.into_iter().enumerate() {
         let Accumulators { map, group_states } = &mut accumulators;
 
-        let entry = map.get_mut(hash, |(existing_hash, group_idx)| {
+        let entry = map.get_mut(hash, |(_hash, group_idx)| {
             // verify that a group that we are inserting with hash is
             // actually the same key value as the group in
             // existing_idx  (aka group_values @ row)
-            if hash != *existing_hash {
-                return false;
-            }
             let group_state = &group_states[*group_idx];
             group_values
                 .iter()