[FLINK-39395][build] Add spotless upToDateChecking

Author: snuyanzin

.gitignore

@@ -13,6 +13,7 @@ scalastyle-output.xml
 .settings
 .project
 .version.properties
+.spotless-index-file
 filter.properties
 logs.zip
 .mvn/wrapper/*.jar

pom.xml

@@ -2203,6 +2203,10 @@ under the License.
 					<version>${spotless.version}</version>
 					<configuration>
 						<skip>${spotless.skip}</skip>
+						<upToDateChecking>
+							<enabled>true</enabled>
+							<indexFile>${project.basedir}/.spotless-index-file</indexFile>
+						</upToDateChecking>
 						<java>
 							<googleJavaFormat>
 								<version>1.7</version>