Bump com.diffplug.spotless:spotless-plugin-gradle

Bumps the gradle-minor group in /build-logic with 1 update: [com.diffplug.spotless:spotless-plugin-gradle](https://github.com/diffplug/spotless).


Updates `com.diffplug.spotless:spotless-plugin-gradle` from 8.3.0 to 8.4.0
- [Release notes](https://github.com/diffplug/spotless/releases)
- [Changelog](https://github.com/diffplug/spotless/blob/main/CHANGES.md)
- [Commits](diffplug/spotless@gradle/8.3.0...gradle/8.4.0)

---
updated-dependencies:
- dependency-name: com.diffplug.spotless:spotless-plugin-gradle
  dependency-version: 8.4.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: gradle-minor
...

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

Author: dependabot[bot]

build-logic/conventions/build.gradle.kts

@@ -9,7 +9,7 @@ repositories {
 
 dependencies {
     implementation("org.jetbrains.kotlin:kotlin-stdlib")
-    implementation("com.diffplug.spotless:spotless-plugin-gradle:8.3.0")
+    implementation("com.diffplug.spotless:spotless-plugin-gradle:8.4.0")
 }
 
 gradlePlugin {