ci: exclude faulty Phoenix node atl1-1-01-002-28-0

Node atl1-1-01-002-28-0 produced illegal-instruction (SIGILL) faults in
pre_process across all case-optimization benchmarks (run 34611616646) and
correlated numerical failures (tolerance mismatches + non-physical phasic
density MPI_ABORT) in the full test suite (run 34673679046). Both jobs
landed on this node; master was intermittently green on the same commit,
indicating a bad node rather than a code regression. Add it to the static
Phoenix GPU exclude list.

Done with Claude Code.

Author: sbryngelson

.github/scripts/submit-slurm-job.sh

@@ -159,7 +159,7 @@ elif [ "$device" = "gpu" ]; then
 #SBATCH -p $gpu_partition
 #SBATCH --ntasks-per-node=4
 #SBATCH -G${gpu_count}"
-            node_exclude="atl1-1-03-007-29-0,atl1-1-03-007-31-0"
+            node_exclude="atl1-1-03-007-29-0,atl1-1-03-007-31-0,atl1-1-01-002-28-0"
             ;;
         frontier|frontier_amd)
             sbatch_device_opts="\