[TEST] Use correct StreamInput version to deserialize in testSnapshot…

…DeletionsInProgressSerialization

The test is currently serializing the cluster state using an older ES version format, but then deserializes those same bytes by
assuming they are of the current ES version.

core/src/test/java/org/elasticsearch/cluster/serialization/ClusterSerializationTests.java

@@ -142,6 +142,7 @@ public void testSnapshotDeletionsInProgressSerialization() throws Exception {
         outStream.setVersion(Version.CURRENT.minimumIndexCompatibilityVersion());
         diffs.writeTo(outStream);
         inStream = outStream.bytes().streamInput();
+        inStream.setVersion(outStream.getVersion());
         inStream = new NamedWriteableAwareStreamInput(inStream, new NamedWriteableRegistry(ClusterModule.getNamedWriteables()));
         serializedDiffs = ClusterState.readDiffFrom(inStream, clusterState.nodes().getLocalNode());
         stateAfterDiffs = serializedDiffs.apply(ClusterState.EMPTY_STATE);