refactor(cubesql): Fix get_first warning

Author: mcheshkov

rust/cubesql/cubesql/Cargo.toml

@@ -97,7 +97,6 @@ collapsible_else_if = "allow"
 comparison_chain = "allow"
 derive_ord_xor_partial_ord = "allow"
 field_reassign_with_default = "allow"
-get_first = "allow"
 identity_op = "allow"
 if_same_then_else = "allow"
 into_iter_on_ref = "allow"

rust/cubesql/cubesql/e2e/tests/postgres.rs

@@ -1269,7 +1269,7 @@ impl AsyncTestSuite for PostgresIntegrationTestSuite {
             |rows| {
                 assert_eq!(rows.len(), 1);
 
-                let columns = rows.get(0).unwrap().columns();
+                let columns = rows.first().unwrap().columns();
                 assert_eq!(
                     columns
                         .into_iter()