[#1550] Disable tests causing IllegalStateException for Db2

See eclipse-vertx/vertx-sql-client#899

Tests throw:
```
java.util.concurrent.CompletionException: java.lang.IllegalStateException: Needed to have 6 in buffer but only had 0. In JDBC we would normally block here but need to find a non-blocking solution
	at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:331) ~[?:?]
	at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:346) ~[?:?]
	at java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:632) ~[?:?]
	at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) ~[?:?]
	at java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2088) ~[?:?]
	at org.hibernate.reactive.pool.impl.Handlers.lambda$toCompletionStage$0(Handlers.java:29) ~[main/:?]
	at io.vertx.sqlclient.impl.SqlResultHandler.fail(SqlResultHandler.java:103)
```

Author: DavideD

hibernate-reactive-core/src/test/java/org/hibernate/reactive/LazyUniqueKeyTest.java

@@ -9,8 +9,10 @@
 
 import org.hibernate.annotations.Fetch;
 import org.hibernate.annotations.FetchMode;
+import org.hibernate.reactive.testing.DatabaseSelectionRule;
 
 import org.junit.Ignore;
+import org.junit.Rule;
 import org.junit.Test;
 
 import jakarta.persistence.CascadeType;
@@ -25,11 +27,18 @@
 import java.util.Collection;
 import java.util.List;
 
+import static org.hibernate.reactive.containers.DatabaseConfiguration.DBType.DB2;
+import static org.hibernate.reactive.testing.DatabaseSelectionRule.skipTestsFor;
+
 /**
  * @see EagerUniqueKeyTest
  */
 public class LazyUniqueKeyTest extends BaseReactiveTest {
 
+	// Db2: java.lang.IllegalStateException: Needed to have 6 in buffer but only had 0. In JDBC we would normally block here
+	@Rule
+	public DatabaseSelectionRule skip = skipTestsFor( DB2 );
+
 	@Override
 	protected Collection<Class<?>> annotatedEntities() {
 		return List.of( Foo.class, Bar.class );

hibernate-reactive-core/src/test/java/org/hibernate/reactive/OrderQueriesTestBase.java

@@ -16,15 +16,19 @@
 import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
 import org.hibernate.cfg.Configuration;
 import org.hibernate.reactive.provider.Settings;
+import org.hibernate.reactive.testing.DatabaseSelectionRule;
 import org.hibernate.reactive.testing.SqlStatementTracker;
 
 import org.junit.After;
+import org.junit.Rule;
 import org.junit.Test;
 
 import io.smallrye.mutiny.Uni;
 import io.vertx.ext.unit.TestContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.hibernate.reactive.containers.DatabaseConfiguration.DBType.DB2;
+import static org.hibernate.reactive.testing.DatabaseSelectionRule.skipTestsFor;
 
 /**
  * Test {@code hibernate.order_updates} and {@code hibernate.order_inserts} configurations.
@@ -34,6 +38,10 @@
  */
 public abstract class OrderQueriesTestBase extends BaseReactiveTest {
 
+	//Db2: java.lang.IllegalStateException: Needed to have 6 in buffer but only had 0. In JDBC we would normally block
+	@Rule
+	public final DatabaseSelectionRule skip = skipTestsFor( DB2 );
+
 	public static class OrderUpdatesTest extends OrderQueriesTestBase {
 
 		@Override

hibernate-reactive-core/src/test/java/org/hibernate/reactive/OrphanRemovalTest.java

@@ -11,6 +11,9 @@
 import java.util.Set;
 
 
+import org.hibernate.reactive.testing.DatabaseSelectionRule;
+
+import org.junit.Rule;
 import org.junit.Test;
 
 import io.vertx.ext.unit.TestContext;
@@ -24,14 +27,18 @@
 import static jakarta.persistence.CascadeType.PERSIST;
 import static jakarta.persistence.CascadeType.REMOVE;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.hibernate.reactive.containers.DatabaseConfiguration.DBType.DB2;
+import static org.hibernate.reactive.testing.DatabaseSelectionRule.skipTestsFor;
 
 public class OrphanRemovalTest extends BaseReactiveTest {
 
+	//Db2: java.lang.IllegalStateException: Needed to have 6 in buffer but only had 0. In JDBC we would normally block
+	@Rule
+	public final DatabaseSelectionRule skip = skipTestsFor( DB2 );
 	@Override
 	protected Collection<Class<?>> annotatedEntities() {
 		return List.of( Shop.class, Version.class, Product.class );
 	}
-
 	@Test
 	public void testOrphan(TestContext context) {
 		Shop shop = new Shop( "shop" );

hibernate-reactive-core/src/test/java/org/hibernate/reactive/SecondaryTableTest.java

@@ -10,6 +10,9 @@
 import java.util.List;
 import java.util.Objects;
 
+import org.hibernate.reactive.testing.DatabaseSelectionRule;
+
+import org.junit.Rule;
 import org.junit.Test;
 
 import io.vertx.ext.unit.TestContext;
@@ -23,9 +26,16 @@
 import jakarta.persistence.Temporal;
 import jakarta.persistence.TemporalType;
 
+import static org.hibernate.reactive.containers.DatabaseConfiguration.DBType.DB2;
+import static org.hibernate.reactive.testing.DatabaseSelectionRule.skipTestsFor;
+
 
 public class SecondaryTableTest extends BaseReactiveTest {
 
+	//Db2: java.lang.IllegalStateException: Needed to have 6 in buffer but only had 0. In JDBC we would normally block
+	@Rule
+	public final DatabaseSelectionRule skip = skipTestsFor( DB2 );
+
 	@Override
 	protected Collection<Class<?>> annotatedEntities() {
 		return List.of( Book.class, Author.class );