[TEST] Removed last occurences of cluster_seed, no longer used

Relates to #5233

TESTING.asciidoc

@@ -200,4 +200,3 @@ insensitive) against it will be executed
 * `tests.seed`: seed to base the random behaviours on
 * `tests.appendseed[true|false]`: enables adding the seed to each test
 section's description (default false)
-* `tests.cluster_seed`: seed used to create the test cluster (if enabled)

pom.xml

@@ -463,7 +463,6 @@
                                 <tests.timeoutSuite>${tests.timeoutSuite}</tests.timeoutSuite>
                                 <tests.showSuccess>${tests.showSuccess}</tests.showSuccess>
                                 <tests.integration>${tests.integration}</tests.integration>
-                                <tests.cluster_seed>${tests.cluster_seed}</tests.cluster_seed>
                                 <tests.client.ratio>${tests.client.ratio}</tests.client.ratio>
                                 <tests.enable_mock_modules>${tests.enable_mock_modules}</tests.enable_mock_modules>
                                 <tests.assertion.disabled>${tests.assertion.disabled}</tests.assertion.disabled>

src/test/java/org/elasticsearch/test/rest/junit/RestTestSuiteRunner.java

@@ -79,7 +79,6 @@ import static org.junit.Assert.assertThat;
  * - tests.iters: runs multiple iterations
  * - tests.seed: seed to base the random behaviours on
  * - tests.appendseed[true|false]: enables adding the seed to each test section's description (default false)
- * - tests.cluster_seed: seed used to create the test cluster (if enabled)
  *
  */
 public class RestTestSuiteRunner extends ParentRunner<RestTestCandidate> {