fix(deps): Update plugin com.diffplug.spotless to v7 (#376)

This PR contains the following updates:

| Package | Type | Update | Change | Pending |
|---|---|---|---|---|
| com.diffplug.spotless | plugin | major | `6.25.0` -> `7.2.1` | `8.0.0` |

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Author: cq-bot

lib/build.gradle

@@ -2,7 +2,7 @@ plugins {
     id 'java-library'
     id "io.freefair.lombok" version "8.14.2"
     id "maven-publish"
-    id "com.diffplug.spotless" version "6.25.0"
+    id "com.diffplug.spotless" version "7.2.1"
 }
 
 ext {