utils: remove unzip_option

`unzip_option` was a workaround for missing `Option::unzip()`, which was
introduced in Rust v1.66.0. We finally bumped the MSRV to 1.66.0, so
`unzip_option` can be removed and replaced with the real thing.

scylla/src/transport/iterator.rs

@@ -38,7 +38,6 @@ use crate::transport::load_balancing::{self, RoutingInfo};
 use crate::transport::metrics::Metrics;
 use crate::transport::retry_policy::{QueryInfo, RetryDecision, RetrySession};
 use crate::transport::{Node, NodeRef};
-use crate::utils::unzip_option;
 use tracing::{trace, trace_span, warn, Instrument};
 use uuid::Uuid;
 
@@ -246,7 +245,7 @@ impl RowIterator {
                     prepared_ref.get_partitioner_name(),
                     values_ref,
                 ) {
-                Ok(res) => unzip_option(res),
+                Ok(res) => res.unzip(),
                 Err(err) => {
                     let (proof, _res) = ProvingSender::from(sender).send(Err(err)).await;
                     return proof;

scylla/src/transport/session.rs

@@ -7,7 +7,6 @@ use crate::cloud::CloudConfig;
 use crate::history;
 use crate::history::HistoryListener;
 use crate::utils::pretty::{CommaSeparatedDisplayer, CqlValueDisplayer};
-use crate::utils::unzip_option;
 use arc_swap::ArcSwapOption;
 use async_trait::async_trait;
 use bytes::Bytes;
@@ -937,11 +936,12 @@ impl Session {
         let values_ref = &serialized_values;
         let paging_state_ref = &paging_state;
 
-        let (partition_key, token) =
-            unzip_option(prepared.extract_partition_key_and_calculate_token(
+        let (partition_key, token) = prepared
+            .extract_partition_key_and_calculate_token(
                 prepared.get_partitioner_name(),
                 &serialized_values,
-            )?);
+            )?
+            .unzip();
 
         let execution_profile = prepared
             .get_execution_profile_handle()

scylla/src/utils/mod.rs

@@ -2,11 +2,3 @@ pub(crate) mod parse;
 
 pub(crate) mod pretty;
 pub mod test_utils;
-
-// FIXME: replace this with `Option::unzip()` once MSRV is bumped to at least 1.66
-pub(crate) fn unzip_option<T, U>(opt: Option<(T, U)>) -> (Option<T>, Option<U>) {
-    match opt {
-        Some((a, b)) => (Some(a), Some(b)),
-        None => (None, None),
-    }
-}