Bump com.approvaltests:approvaltests from 20.0.0 to 21.0.0

Bumps [com.approvaltests:approvaltests](https://github.com/approvals/ApprovalTests.Java) from 20.0.0 to 21.0.0.
- [Release notes](https://github.com/approvals/ApprovalTests.Java/releases)
- [Commits](approvals/ApprovalTests.Java@20.0.0...21.0.0)

---
updated-dependencies:
- dependency-name: com.approvaltests:approvaltests
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

app/build.gradle

@@ -29,7 +29,7 @@ dependencies {
     // Use the awesome Spock testing and specification framework even with Java
     testImplementation 'org.spockframework:spock-core:2.1-groovy-3.0'
     testImplementation 'org.junit.jupiter:junit-jupiter:5.10.0'
-    testImplementation("com.approvaltests:approvaltests:20.0.0")
+    testImplementation("com.approvaltests:approvaltests:21.0.0")
     testImplementation("com.google.code.gson:gson:2.10.1")
 }