Bump testng from 6.9.10 to 7.6.1

Bumps [testng](https://github.com/cbeust/testng) from 6.9.10 to 7.6.1.
- [Release notes](https://github.com/cbeust/testng/releases)
- [Changelog](https://github.com/cbeust/testng/blob/master/CHANGES.txt)
- [Commits](testng-team/testng@6.9.10...7.6.1)

---
updated-dependencies:
- dependency-name: org.testng:testng
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

build.gradle

@@ -46,7 +46,7 @@ dependencies {
     compileOnly 'com.squareup.okhttp3:okhttp:4.10.0' // method count bloat
     compileOnly 'com.google.appengine:appengine-api-1.0-sdk:1.9.38'
 
-    testImplementation 'org.testng:testng:6.9.10'
+    testImplementation 'org.testng:testng:7.6.1'
     testImplementation 'org.mockito:mockito-core:1.10.19'
     testImplementation 'org.openjdk.jmh:jmh-core:1.12'
     testImplementation 'org.openjdk.jmh:jmh-generator-annprocess:1.35'