remove unused functions in SortExec (#16457)

Author: adriangb

datafusion/physical-plan/src/sorts/sort.rs

@@ -935,11 +935,6 @@ impl SortExec {
         }
     }
 
-    pub fn with_filter(mut self, filter: Arc<DynamicFilterPhysicalExpr>) -> Self {
-        self.filter = Some(filter);
-        self
-    }
-
     /// Input schema
     pub fn input(&self) -> &Arc<dyn ExecutionPlan> {
         &self.input
@@ -955,11 +950,6 @@ impl SortExec {
         self.fetch
     }
 
-    /// If `Some(filter)`, returns the filter expression that matches the state of the sort.
-    pub fn filter(&self) -> Option<Arc<DynamicFilterPhysicalExpr>> {
-        self.filter.clone()
-    }
-
     fn output_partitioning_helper(
         input: &Arc<dyn ExecutionPlan>,
         preserve_partitioning: bool,