Bump org.testng:testng from 6.13.1 to 7.5.1 in /functional-tests

Bumps [org.testng:testng](https://github.com/cbeust/testng) from 6.13.1 to 7.5.1.
- [Release notes](https://github.com/cbeust/testng/releases)
- [Changelog](https://github.com/testng-team/testng/blob/master/CHANGES.txt)
- [Commits](testng-team/testng@6.13.1...7.5.1)

---
updated-dependencies:
- dependency-name: org.testng:testng
  dependency-type: direct:development
...

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

Author: dependabot[bot]

functional-tests/pom.xml

@@ -103,7 +103,7 @@
         <dependency>
             <groupId>org.testng</groupId>
             <artifactId>testng</artifactId>
-            <version>6.13.1</version>
+            <version>7.5.1</version>
             <scope>test</scope>
         </dependency>
     </dependencies>