Bump com.github.spotbugs from 5.2.1 to 6.0.4

Bumps com.github.spotbugs from 5.2.1 to 6.0.4.

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

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

build.gradle

@@ -2,7 +2,7 @@ plugins {
   id "com.jfrog.bintray" version "1.8.5"
   id "java"
   id "checkstyle"
-  id "com.github.spotbugs" version "5.2.1"
+  id "com.github.spotbugs" version "6.0.4"
   id "org.sonarqube" version "4.0.0.2929"
 
   id "maven-publish"