Bump org.mockito:mockito-junit-jupiter from 5.20.0 to 5.21.0

Bumps [org.mockito:mockito-junit-jupiter](https://github.com/mockito/mockito) from 5.20.0 to 5.21.0.
- [Release notes](https://github.com/mockito/mockito/releases)
- [Commits](mockito/mockito@v5.20.0...v5.21.0)

---
updated-dependencies:
- dependency-name: org.mockito:mockito-junit-jupiter
  dependency-version: 5.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

build.gradle.kts

@@ -26,7 +26,7 @@ dependencies {
     testImplementation("org.junit.jupiter:junit-jupiter-api:6.0.1")
     testImplementation("org.apache.flink:flink-test-utils:$flinkVersion")
     testImplementation("org.assertj:assertj-core:3.27.6")
-    testImplementation("org.mockito:mockito-junit-jupiter:5.20.0")
+    testImplementation("org.mockito:mockito-junit-jupiter:5.21.0")
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
     testRuntimeOnly("org.slf4j:slf4j-simple:2.0.17")
@@ -52,7 +52,7 @@ testing {
                 implementation("org.junit.jupiter:junit-jupiter-api:$junitVersion")
                 implementation("org.apache.flink:flink-test-utils:$flinkVersion")
 
-                implementation("org.mockito:mockito-junit-jupiter:5.20.0")
+                implementation("org.mockito:mockito-junit-jupiter:5.21.0")
 
                 runtimeOnly("org.junit.jupiter:junit-jupiter-engine:$junitVersion")
                 runtimeOnly("org.slf4j:slf4j-simple:2.0.17")