fix(tools): invoke remote_monitor via python3.11 on nodes

The experiment Python stack (prometheus-client requirements, promql-parser,
and the local promql_utilities package) is installed only under python3.11 on
the CloudLab nodes (see installation/common/setup_dependencies.sh). system
python3 lacks these (and loguru on some nodes), so remote_monitor.py - which
imports PrometheusClientService - must run under python3.11.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: akanksha-akkihal

asap-tools/experiments/experiment_utils/services/remote_monitor_service.py

@@ -111,7 +111,10 @@ def start(
         if use_timed_mode:
             # Build command for timed mode (skip_querying)
             cmd = (
-                "python3 -u remote_monitor.py "
+                # python3.11: the experiment stack (prometheus-client reqs,
+                # promql-parser, promql_utilities) is installed only under
+                # python3.11 on the nodes; system python3 lacks them.
+                "python3.11 -u remote_monitor.py "
                 "--execution_mode timed "
                 "--experiment_mode {} "
                 r"--keywords \"{}\" "
@@ -164,7 +167,8 @@ def start(
         assert controller_remote_output_dir is not None
 
         cmd = (
-            "python3 -u remote_monitor.py "
+            # python3.11: see note above; experiment deps live under python3.11.
+            "python3.11 -u remote_monitor.py "
             "--execution_mode prometheus_client "
             "--experiment_mode {} "
             r"--keywords \"{}\" "