Investigate requirement for tools.jar dependency in systemtest

**Summary**

Do any tests require tools.jar to function? Can we delete that dependency, and simply use:
- JDK8: The tools.jar in the jdk.
- JDK9+: Nothing (in Java 9, tools.jar classes were merged into modules).

**Details**

One of the dependency files used by the aqa system tests is tools.jar.

This file exists in JDK8 only, as the classes were integrated into modules for JDK9+.

In the jenkins job [systemtest.getDependency](https://ci.adoptium.net/job/systemtest.getDependency), we download the latest Temurin JDK for xLinux and we extract the tools.jar, storing it as a jenkins artifact.

When the system test jobs are run, we download the artifacts from that job and put them in the systemtest_prereqs directory for use in some of the tests.

We need to investigate whether the tools.jar is actually required at run time, to remove a layer of complexity and maintenance from the project.

Note: JDK8 may need to keep tools.jar on the classpath, but we should explore the option of using the one included in the JDK.

**Links**

- https://github.com/adoptium/TKG/pull/785#
- https://ci.adoptium.net/job/systemtest.getDependency

Start by tracing references to tools.jar in the systemtest_prereqs artifacts and the systemtest.getDependency Jenkins job, then review the linked TKG pull request for context. Determine whether any system tests require the separately extracted dependency and verify the result across JDK8 and JDK9+; done means the artifact can be removed safely or its remaining requirement is documented.

Written by the indexing model from the issue text.