Fix environment with force-purged modules

Also specify `torchvision` version. It's not perfect since it's still
prone to breakage, but at least we forbid known not working versions.

Thanks to @khalfaoui1 for reporting it.

pytorch-ddp-example/requirements.txt

 torch>=1.9,<3
 torchrun_jsc>=0.0.4
-torchvision
+torchvision>=0.13

pytorch-ddp-example/run.sbatch

@@ -20,7 +20,8 @@ export SRUN_CPUS_PER_TASK="$SLURM_CPUS_PER_TASK"
 
 [ -x "$(command -v deactivate)" ] && deactivate
 
-module purge
+module --force purge
+module load Stages
 source "$curr_dir"/modules.sh
 
 if ! [ -d "$curr_dir"/env ]; then

pytorch-fsdp-example/requirements.txt

 torch>=2,<3
 torchrun_jsc>=0.0.4
-torchvision
+torchvision>=0.13

pytorch-fsdp-example/run.sbatch

@@ -20,7 +20,8 @@ export SRUN_CPUS_PER_TASK="$SLURM_CPUS_PER_TASK"
 
 [ -x "$(command -v deactivate)" ] && deactivate
 
-module purge
+module --force purge
+module load Stages
 source "$curr_dir"/modules.sh
 
 if ! [ -d "$curr_dir"/env ]; then