Update dependency com.puppycrawl.tools:checkstyle to v10.21.1 (#2778)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

pom.xml

@@ -1973,7 +1973,7 @@ under the License.
 							<groupId>com.puppycrawl.tools</groupId>
 							<artifactId>checkstyle</artifactId>
 							<!-- Note: match version with docs/flinkDev/ide_setup.md -->
-							<version>10.21.0</version>
+							<version>10.21.1</version>
 						</dependency>
 					</dependencies>
 					<executions>