Bump checkstyle from 6.17 to 8.18

Bumps [checkstyle](https://github.com/checkstyle/checkstyle) from 6.17 to 8.18.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-6.17...checkstyle-8.18)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pom.xml

@@ -53,7 +53,7 @@
         <dependency>
             <groupId>com.puppycrawl.tools</groupId>
             <artifactId>checkstyle</artifactId>
-            <version>6.17</version>
+            <version>8.18</version>
         </dependency>
 
         <dependency>
@@ -118,7 +118,7 @@
                         <dependency>
                             <groupId>com.puppycrawl.tools</groupId>
                             <artifactId>checkstyle</artifactId>
-                            <version>6.17</version>
+                            <version>8.18</version>
                         </dependency>
                     </dependencies>
                 </plugin>