Bump de.gesellix:testutil

Bumps [de.gesellix:testutil](https://github.com/docker-client/testutil) from 2023-07-02T11-35-00 to 2023-08-15T20-58-00.
- [Release notes](https://github.com/docker-client/testutil/releases)
- [Changelog](https://github.com/docker-client/testutil/blob/main/RELEASE.md)
- [Commits](https://github.com/docker-client/testutil/commits)

---
updated-dependencies:
- dependency-name: de.gesellix:testutil
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

engine/build.gradle.kts

@@ -80,7 +80,7 @@ dependencies {
   testImplementation("org.apache.commons:commons-lang3:3.13.0")
 
   implementation("de.gesellix:docker-filesocket:2023-07-11T22-35-00")
-  testImplementation("de.gesellix:testutil:2023-07-02T11-35-00")
+  testImplementation("de.gesellix:testutil:2023-08-15T20-58-00")
 
   implementation("org.bouncycastle:bcpkix-jdk15on:1.70")