Bump com.github.spotbugs from 6.0.5 to 6.0.18

Bumps com.github.spotbugs from 6.0.5 to 6.0.18.

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

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

build.gradle

@@ -10,7 +10,7 @@ plugins {
   id 'io.freefair.lombok' version "${freefairVersion}" // apply, because javadoc
   id  'com.netflix.nebula.project' version '11.0.0' apply false
   id 'com.palantir.git-version' version '3.0.0'
-  id 'com.github.spotbugs' version '6.0.5' apply false
+  id 'com.github.spotbugs' version '6.0.18' apply false
   id 'io.freefair.maven-optional' version "${freefairVersion}"
   id 'com.github.jk1.dependency-license-report' version '2.5'
   id 'io.spring.dependency-management' version '1.1.4' apply false