build(deps): bump com.diffplug.spotless from 8.5.1 to 8.6.0

Bumps com.diffplug.spotless from 8.5.1 to 8.6.0.

---
updated-dependencies:
- dependency-name: com.diffplug.spotless
  dependency-version: 8.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

build.gradle

@@ -1,7 +1,7 @@
 plugins {
     id 'base'
     id 'net.ltgt.errorprone'  version '5.0.0' apply false
-    id 'com.diffplug.spotless' version '8.5.1' apply false
+    id 'com.diffplug.spotless' version '8.6.0' apply false
     id 'java'
 }