[HUDI-1869] [MINOR] add slf4j dependencies for UT

Author: YannByron

hudi-spark-datasource/hudi-spark/pom.xml

@@ -503,6 +503,13 @@
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+      <version>${slf4j.version}</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>org.apache.hadoop</groupId>
       <artifactId>hadoop-hdfs</artifactId>