[test] Concurrent Unit Tests in Catloop and Catmem
## Description

Our `demikernel_ci` utility launches unit tests on server and client machines.

For Catmem and Catloop LibOses, this means that we run two instances of unit-tests in the same machine, thus causing them to conflict and interfere in one another.

## Code Snippet

https://github.com/demikernel/demikernel/blob/adcae5ed3fe87879fda324bc4dc3a46794391914/tools/demikernel_ci.py#L142-L150

## Expected Behavior

For Catmem and Catloop LibOSes we should run unit tests in either the server or client endpoint.


diff --git a/tools/demikernel_ci.py b/tools/demikernel_ci.py
index be70ff30..b0af1bd0 100644
--- a/tools/demikernel_ci.py
+++ b/tools/demikernel_ci.py
@@ -146,7 +146,7 @@ def job_test_unit_rust(repo: str, libos: str, is_debug: bool, server: str, clien
     test_name = "unit-test"
     jobs: dict[str, subprocess.Popen[str]] = {}
     jobs[test_name + "-server-" + server] = remote_run(server, repo, is_debug, server_cmd, is_sudo, config_path)
-    jobs[test_name + "-client-" + client] = remote_run(client, repo, is_debug, client_cmd, is_sudo, config_path)
+    # Unit tests require a single endpoint, so do not run them on client.
     return wait_and_report(test_name, log_directory, jobs, True)
 
 
['tools/demikernel_ci.py']