Bump org.assertj:assertj-core from 3.26.0 to 3.26.3

Bumps [org.assertj:assertj-core](https://github.com/assertj/assertj) from 3.26.0 to 3.26.3.
- [Release notes](https://github.com/assertj/assertj/releases)
- [Commits](assertj/assertj@assertj-build-3.26.0...assertj-build-3.26.3)

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

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

build.gradle

@@ -117,7 +117,7 @@ dependencies {
 
     testImplementation project.deps.gocdPluginApi
     testImplementation group: 'uk.org.webcompere', name: 'system-stubs-jupiter', version: '2.1.6'
-    testImplementation group: 'org.assertj', name: 'assertj-core', version: '3.26.0'
+    testImplementation group: 'org.assertj', name: 'assertj-core', version: '3.26.3'
     testImplementation platform('org.mockito:mockito-bom:5.12.0')
     testImplementation group: 'org.mockito', name: 'mockito-core'
     testImplementation group: 'org.skyscreamer', name: 'jsonassert', version: '1.5.3'