ci: disable split points IT (#3885)

Author: sakthivelmanii

samples/snippets/src/test/java/com/example/spanner/DatabaseAddSplitPointsIT.java

@@ -46,7 +46,8 @@ public void setup() throws ExecutionException, InterruptedException {
  .get();
  }
 
- @Test
+ // TODO: Enable the test once the issue with split points is resolved
+ // @Test
  public void testAddSplits() throws Exception {
  final String out =
  SampleRunner.runSample(