chore(deps): bump com.diffplug.spotless:spotless-plugin-gradle

Bumps [com.diffplug.spotless:spotless-plugin-gradle](https://github.com/diffplug/spotless) from 7.2.1 to 8.9.0.
- [Release notes](https://github.com/diffplug/spotless/releases)
- [Changelog](https://github.com/diffplug/spotless/blob/main/CHANGES.md)
- [Commits](diffplug/spotless@gradle/7.2.1...gradle/8.9.0)

---
updated-dependencies:
- dependency-name: com.diffplug.spotless:spotless-plugin-gradle
  dependency-version: 8.9.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

build-logic/conventions/build.gradle.kts

@@ -8,7 +8,7 @@ repositories {
 }
 
 dependencies {
-    implementation("com.diffplug.spotless:spotless-plugin-gradle:7.2.1")
+    implementation("com.diffplug.spotless:spotless-plugin-gradle:8.9.0")
     implementation("com.vanniktech.maven.publish:com.vanniktech.maven.publish.gradle.plugin:0.34.0")
 }