Bump com.diffplug.spotless from 8.8.0 to 8.9.0

Bumps com.diffplug.spotless from 8.8.0 to 8.9.0.

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

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

Author: dependabot[bot]

gradle/libs.versions.toml

@@ -10,7 +10,7 @@ ktor = "3.5.1"
 logback = "1.5.38"
 postgresql = "42.7.13"
 slugify = "4.0.1"
-spotless = "8.8.0"
+spotless = "8.9.0"
 sqldelight = "2.3.2"
 testcontainers = "1.21.4"
 version-catalog-update = "1.1.0"