Fixes the build.

Use JUnit 4 instead of 5 for 1.1.x
Remove jetbrains @NotNull annotation.

Closes #921

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/PersistentPropertyPathExtensionUnitTests.java

@@ -17,7 +17,6 @@ package org.springframework.data.jdbc.core;
 
 import java.util.List;
 
-import org.jetbrains.annotations.NotNull;
 import org.junit.Test;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.jdbc.core.mapping.JdbcMappingContext;
@@ -200,12 +199,10 @@ public class PersistentPropertyPathExtensionUnitTests {
 		});
 	}
 
-	@NotNull
 	private PersistentPropertyPathExtension extPath(RelationalPersistentEntity<?> entity) {
 		return new PersistentPropertyPathExtension(context, entity);
 	}
 
-	@NotNull
 	private PersistentPropertyPathExtension extPath(String path) {
 		return new PersistentPropertyPathExtension(context, createSimplePath(path));
 	}

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/mapping/PersistentPropertyPathTestUtils.java

@@ -17,7 +17,6 @@ package org.springframework.data.jdbc.core.mapping;
 
 import lombok.experimental.UtilityClass;
 
-import org.jetbrains.annotations.NotNull;
 import org.springframework.data.mapping.PersistentPropertyPath;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
 import org.springframework.data.relational.core.mapping.RelationalPersistentProperty;
@@ -28,7 +27,6 @@ import org.springframework.data.relational.core.mapping.RelationalPersistentProp
 @UtilityClass
 public class PersistentPropertyPathTestUtils {
 
-	@NotNull
 	public static PersistentPropertyPath<RelationalPersistentProperty> getPath(RelationalMappingContext context,
 			String path, Class<?> baseType) {
 

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/config/EnableJdbcAuditingHsqlIntegrationTests.java

@@ -26,7 +26,6 @@ import java.util.concurrent.TimeUnit;
 import java.util.function.Consumer;
 
 import org.assertj.core.api.SoftAssertions;
-import org.jetbrains.annotations.NotNull;
 import org.junit.Test;
 import org.springframework.context.ApplicationListener;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -271,7 +270,7 @@ public class EnableJdbcAuditingHsqlIntegrationTests {
 
 			return new NamingStrategy() {
 
-				public String getTableName(@NotNull Class<?> type) {
+				public String getTableName(Class<?> type) {
 					return "DummyEntity";
 				}
 			};

spring-data-relational/src/test/java/org/springframework/data/relational/core/sql/ConditionsUnitTests.java

@@ -5,7 +5,7 @@ import static org.assertj.core.api.Assertions.*;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 /*
  * Copyright 2021 the original author or authors.
@@ -22,10 +22,10 @@ import org.junit.jupiter.api.Test;
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-class ConditionsUnitTests {
+public class ConditionsUnitTests {
 
 	@Test // gh-916
-	void notInOfColumnAndExpression() {
+	public void notInOfColumnAndExpression() {
 
 		Table table = Table.create("t");
 		Column column = Column.create("col", table);