Dependency(deps): Bump com.github.spotbugs:spotbugs from 4.8.3 to 4.8.4

Bumps [com.github.spotbugs:spotbugs](https://github.com/spotbugs/spotbugs) from 4.8.3 to 4.8.4.
- [Release notes](https://github.com/spotbugs/spotbugs/releases)
- [Changelog](https://github.com/spotbugs/spotbugs/blob/master/CHANGELOG.md)
- [Commits](spotbugs/spotbugs@4.8.3...4.8.4)

---
updated-dependencies:
- dependency-name: com.github.spotbugs:spotbugs
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

autograder-core/pom.xml

@@ -114,7 +114,7 @@
         <dependency>
             <groupId>com.github.spotbugs</groupId>
             <artifactId>spotbugs</artifactId>
-            <version>4.8.3</version>
+            <version>4.8.4</version>
             <exclusions>
                 <exclusion>
                     <groupId>org.slf4j</groupId>