build(deps): bump com.puppycrawl.tools:checkstyle in /server

Bumps [com.puppycrawl.tools:checkstyle](https://github.com/checkstyle/checkstyle) from 10.21.3 to 10.21.4.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](https://github.com/checkstyle/checkstyle/compare/checkstyle-10.21.3...checkstyle-10.21.4)

---
updated-dependencies:
- dependency-name: com.puppycrawl.tools:checkstyle
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

server/pom.xml

@@ -419,7 +419,7 @@
           <dependency>
             <groupId>com.puppycrawl.tools</groupId>
             <artifactId>checkstyle</artifactId>
-            <version>10.21.3</version>
+            <version>10.21.4</version>
           </dependency>
         </dependencies>
         <configuration>