Bump the gradle group in /codegen with 2 updates (#667)

Bumps the gradle group in /codegen with 2 updates: [gradle-wrapper](https://github.com/gradle/gradle) and [com.diffplug.spotless:spotless-plugin-gradle](https://github.com/diffplug/spotless).


Updates `gradle-wrapper` from 9.4.0 to 9.4.1
- [Release notes](https://github.com/gradle/gradle/releases)
- [Commits](gradle/gradle@v9.4.0...v9.4.1)

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: gradle-wrapper
  dependency-version: 9.4.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: gradle
- 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
...

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

Author: dependabot[bot]

codegen/gradle/libs.versions.toml

@@ -4,7 +4,7 @@ smithy = "1.68.0"
 mockito = "5.23.0"
 test-logger-plugin = "4.0.0"
 spotbugs = "6.0.22"
-spotless = "8.3.0"
+spotless = "8.4.0"
 smithy-gradle-plugins = "1.4.0"
 dep-analysis = "3.6.1"
 jsoup = "1.22.1"

codegen/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME