Bump spotless-plugin-gradle from 6.0.0 to 6.12.0 (#130)

Bumps [spotless-plugin-gradle](https://github.com/diffplug/spotless) from 6.0.0 to 6.12.0.
- [Release notes](https://github.com/diffplug/spotless/releases)
- [Changelog](https://github.com/diffplug/spotless/blob/main/CHANGES.md)
- [Commits](diffplug/spotless@gradle/6.0.0...gradle/6.12.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

buildSrc/build.gradle.kts

@@ -19,7 +19,7 @@ val buildToolsVersion = "7.0.3"
 val kotlinVersion = "1.4.32"
 val dokkaVersion = "1.4.32"
 val manesVersion = "0.38.0"
-val spotlessVersion = "6.0.0"
+val spotlessVersion = "6.12.0"
 
 dependencies {
     /* Depend on the android gradle plugin, since we want to access it in our plugin */