Bump uk.org.webcompere:system-stubs-jupiter from 2.1.2 to 2.1.3

Bumps [uk.org.webcompere:system-stubs-jupiter](https://github.com/webcompere/system-stubs) from 2.1.2 to 2.1.3.
- [Release notes](https://github.com/webcompere/system-stubs/releases)
- [Changelog](https://github.com/webcompere/system-stubs/blob/main/History.md)
- [Commits](webcompere/system-stubs@system-stubs-parent-2.1.2...system-stubs-parent-2.1.3)

---
updated-dependencies:
- dependency-name: uk.org.webcompere:system-stubs-jupiter
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

build.gradle

@@ -120,7 +120,7 @@ dependencies {
     testRuntimeOnly group: 'org.junit.platform', name: 'junit-platform-launcher'
 
     testImplementation project.deps.gocdPluginApi
-    testImplementation group: 'uk.org.webcompere', name: 'system-stubs-jupiter', version: '2.1.2'
+    testImplementation group: 'uk.org.webcompere', name: 'system-stubs-jupiter', version: '2.1.3'
     testImplementation group: 'org.assertj', name: 'assertj-core', version: '3.24.2'
     testImplementation platform('org.mockito:mockito-bom:5.5.0')
     testImplementation group: 'org.mockito', name: 'mockito-core'