Use rmw_test_fixture to isolate ros2cli tests (backport #1062)

[mergify]

Description

Use the rmw_test_isolation system for creating a communication sandbox for each test.

Fixes # (issue)

Is this user-facing behavior change?

Yes, ros2cli.helpers.get_rmw_additional_env will no longer enable multicast for Zenoh.

Did you use Generative AI?

No

---

This is an automatic backport of pull request #1062 done by [Mergify](https://mergify.com).

[Blast545]

Running CI without this PR, trying to reproduce the problem:

Running CI with this PR, trying to test the fix:

[Blast545]

Attempt to replicate number 2, this time including other packages that are raising test errors in the current Kilted release jobs. Under the assumption that maybe one of thoses are not shutting down things properly, making later this test fail.

[fujitatomoya]

@Blast545 after all, we are not able to reproduce the flaky result?

btw, if we are backporting this, we should also take #1098?

[Blast545]

@fujitatomoya I'll do a couple of extra attempts before giving up on replicating it. Tricky part would be trying to reproduce it on ci.ros2.org since the job with the regression it's on build.ros2.org.

I added to this PR the commit that you referenced, I'm not sure if I'm missing something from the commits that were in the middle of those two but I will give a check in a bit.

[Blast545]

Re-running with extra commit from #1098 backported

[Blast545]

Extra attempt to REPLICATE the problem:

I'm running the whole suite now that CI doesn't have a big load, and I disabled sequential tests executor, which seemed like a significant difference from the build in build.ros2.org vs the default ci.ros2.org configurations.

[Blast545]

I was able to replicate the problem locally using the ros_buildfarm scripts:

git clone [email protected]:ros-infrastructure/ros_buildfarm.git
cd ros_buildfarm/scripts/ci/
./generate_ci_script.py https://raw.githubusercontent.com/ros2/ros_buildfarm_config/ros2/index.yaml kilted nightly-release ubuntu noble amd64 > ci_job_kilted_all.sh
sh ci_job_kilted_all.sh

I'm taking a look to see how to modify the generated script to get access to the docker environment running the tests, and troubleshoot what's left open when the tests are run.