Bump org.assertj:assertj-core in /modules/toxiproxy

Bumps [org.assertj:assertj-core](https://github.com/assertj/assertj) from 3.24.2 to 3.25.3.
- [Release notes](https://github.com/assertj/assertj/releases)
- [Commits](assertj/assertj@assertj-build-3.24.2...assertj-build-3.25.3)

---
updated-dependencies:
- dependency-name: org.assertj:assertj-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

modules/toxiproxy/build.gradle

@@ -5,5 +5,5 @@ dependencies {
     api 'eu.rekawek.toxiproxy:toxiproxy-java:2.1.7'
 
     testImplementation 'redis.clients:jedis:3.0.1'
-    testImplementation 'org.assertj:assertj-core:3.24.2'
+    testImplementation 'org.assertj:assertj-core:3.25.3'
 }