chore(deps): bump com.gradleup.shadow in /custom-user-federation-example (#1288)

Bumps [com.gradleup.shadow](https://github.com/GradleUp/shadow) from 8.3.8 to 9.1.0.
- [Release notes](https://github.com/GradleUp/shadow/releases)
- [Commits](GradleUp/shadow@8.3.8...9.1.0)

---
updated-dependencies:
- dependency-name: com.gradleup.shadow
  dependency-version: 9.1.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Sebastian Schuster <[email protected]>

Author: dependabot[bot]

custom-user-federation-example/build.gradle

@@ -1,6 +1,6 @@
 plugins {
 	id 'org.jetbrains.kotlin.jvm' version '2.2.10'
-	id 'com.gradleup.shadow' version '8.3.8'
+	id 'com.gradleup.shadow' version '9.1.0'
 	id 'java-library'
 }