Fix SLURM RAM monitoring

[benoit-cty]

Fix SLURM RAM monitoring :

• Fix error when calling scontrol
• Do only one call instead of one at each measure

Will close #447

[benoit-cty]

Tested on a SLURM environment : there is only too call per sessions and no more error message.

[SaboniAmine]

Thanks Benoît! Small comment about the notebook, not sure we want to merge it to master

[vict0rsch]

I'll have a look next week 😊

[vict0rsch]

There was an issue with $SLURM_JOBID which was changed to $SLURM_JOB_ID, making some queries like scontrol show job $SLURM_JOBID" fail.

[vict0rsch]

This works as expected

from codecarbon.external.hardware import RAM

ram = RAM(tracking_mode="process")
ram.slurm_memory_GB

[benoit-cty]

There was an issue with $SLURM_JOBID which was changed to $SLURM_JOB_ID, making some queries like scontrol show job $SLURM_JOBID" fail.

Thanks for your review, it seems to be deprecated since 2017 so it is safe to remove the support of the old name !