[hotfix] Remove unused DurableExecutionManager.maybePruneState helper (#682)

Author: weiqingy

runtime/src/main/java/org/apache/flink/agents/runtime/operator/DurableExecutionManager.java

@@ -319,12 +319,6 @@ public void persist(
         }
     }
 
-    void maybePruneState(Object key, long sequenceNum) throws Exception {
-        if (actionStateStore != null) {
-            actionStateStore.pruneState(key, sequenceNum);
-        }
-    }
-
     /**
      * Prunes durable state for all per-key sequence numbers that were captured at the time of the
      * given checkpoint.

runtime/src/test/java/org/apache/flink/agents/runtime/operator/DurableExecutionManagerTest.java

@@ -65,7 +65,6 @@ void noStoreModeMakesAllMaybeOperationsNoOp() throws Exception {
         // Every maybe* method must be a silent no-op.
         assertThat(dem.maybeGetActionState("k", 0L, action, event)).isNull();
         dem.maybeInitActionState("k", 0L, action, event);
-        dem.maybePruneState("k", 0L);
         dem.notifyCheckpointComplete(1L);
         dem.snapshotRecoveryMarker();
         dem.close();