Bump org.testfx:openjfx-monocle from 17.0.10 to 21.0.2

Bumps [org.testfx:openjfx-monocle](https://github.com/TestFX/Monocle) from 17.0.10 to 21.0.2.
- [Release notes](https://github.com/TestFX/Monocle/releases)
- [Commits](https://github.com/TestFX/Monocle/commits)

---
updated-dependencies:
- dependency-name: org.testfx:openjfx-monocle
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

build.gradle

@@ -57,7 +57,7 @@ dependencies {
 
     testImplementation 'org.junit.jupiter:junit-jupiter:5.10.2'
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
-    testImplementation 'org.testfx:openjfx-monocle:17.0.10'
+    testImplementation 'org.testfx:openjfx-monocle:21.0.2'
 }
 
 javafx {