Fix IncrementalDataScalingTask execute fail in unit tests bug. (#7991)

* Fix IncrementalDataScalingTask execute fail in unit tests bug

Co-authored-by: qiulu3 <Lucas209910>

shardingsphere-scaling/shardingsphere-scaling-bootstrap/src/test/java/org/apache/shardingsphere/scaling/web/HttpServerHandlerTest.java

@@ -64,8 +64,10 @@ public final class HttpServerHandlerTest {
     @Before
     @SneakyThrows(ReflectiveOperationException.class)
     public void setUp() {
-        ScalingContext.getInstance().init(new ServerConfiguration());
-        ReflectionUtil.setFieldValue(ScalingContext.getInstance(), "taskExecuteEngine", mock(ShardingScalingExecuteEngine.class));
+        if (null == ScalingContext.getInstance().getServerConfig()) {
+            ScalingContext.getInstance().init(new ServerConfiguration());
+            ReflectionUtil.setFieldValue(ScalingContext.getInstance(), "taskExecuteEngine", mock(ShardingScalingExecuteEngine.class));
+        }
     }
     
     @Test

shardingsphere-scaling/shardingsphere-scaling-core/src/test/java/org/apache/shardingsphere/scaling/core/ScalingJobControllerTest.java

@@ -52,8 +52,10 @@ public final class ScalingJobControllerTest {
     @Before
     @SneakyThrows(ReflectiveOperationException.class)
     public void setUp() {
-        ScalingContext.getInstance().init(new ServerConfiguration());
-        ReflectionUtil.setFieldValue(ScalingContext.getInstance(), "taskExecuteEngine", mock(ShardingScalingExecuteEngine.class));
+        if (null == ScalingContext.getInstance().getServerConfig()) {
+            ScalingContext.getInstance().init(new ServerConfiguration());
+            ReflectionUtil.setFieldValue(ScalingContext.getInstance(), "taskExecuteEngine", mock(ShardingScalingExecuteEngine.class));
+        }
     }
     
     @Test