Fix assertion in testReturnsImmediatelyIfVoteAlreadyWithdrawn

This test is today asserting that the _initial_ state has all the
expected exclusions, but it should be checking the _final_ state.

Relates elastic#98386

server/src/test/java/org/elasticsearch/action/admin/cluster/configuration/TransportAddVotingConfigExclusionsActionTests.java

@@ -232,8 +232,9 @@ public void testReturnsImmediatelyIfVoteAlreadyWithdrawn() {
             new AddVotingConfigExclusionsRequest("other1"),
             expectSuccess(r -> {
                 assertNotNull(r);
-                assertThat(clusterService.getClusterApplierService().state().getVotingConfigExclusions(), contains(otherNode1Exclusion));
-                assertAllExclusionsApplied(state);
+                final var finalState = clusterService.getClusterApplierService().state();
+                assertThat(finalState.getVotingConfigExclusions(), contains(otherNode1Exclusion));
+                assertAllExclusionsApplied(finalState);
                 countDownLatch.countDown();
             })
         );