Update prometheus-slurm-exporter version

[m-bull]

prometheus-slurm-exporter 0.20 fails to parse GRES output for Slurm >19.05.0rc1 and just ends up in a crash loop.

Update versions to point to new RPM (https://github.com/stackhpc/prometheus-slurm-exporter/releases/tag/0.21) built from the development branch of https://github.com/stackhpc/prometheus-slurm-exporter, which has the relevant fixes in.

[m-bull]

Version 0.20 logs this:

May 31 18:57:14 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: time="2023-05-31T18:57:14Z" level=info msg="Starting Server: 0.0.0.0:9341" source="main.go:59"
May 31 18:57:14 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: time="2023-05-31T18:57:14Z" level=info msg="GPUs Accounting: false" source="main.go:60"
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: panic: runtime error: index out of range [4] with length 4
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: goroutine 40 [running]:
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: main.ParseNodeMetrics(0xc000436000, 0xca, 0x600, 0x88f973)
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]:         /github/home/rpmbuild/BUILD/prometheus-slurm-exporter-0.20/node.go:56 +0x6d6
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: main.NodeGetMetrics(0x1)
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]:         /github/home/rpmbuild/BUILD/prometheus-slurm-exporter-0.20/node.go:40 +0x2a
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: main.(*NodeCollector).Collect(0xc00007fdd0, 0xc000070ea0)
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]:         /github/home/rpmbuild/BUILD/prometheus-slurm-exporter-0.20/node.go:128 +0x37
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: github.com/prometheus/client_golang/prometheus.(*Registry).Gather.func1()
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]:         /github/home/go/pkg/mod/github.com/prometheus/[email protected]/prometheus/registry.go:443 +0x12b
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]: created by github.com/prometheus/client_golang/prometheus.(*Registry).Gather
May 31 18:57:18 matta-slurm-control-0.novalocal prometheus-slurm-exporter[64809]:         /github/home/go/pkg/mod/github.com/prometheus/[email protected]/prometheus/registry.go:535 +0xe4d
May 31 18:57:18 matta-slurm-control-0.novalocal systemd[1]: prometheus-slurm-exporter.service: Main process exited, code=exited, status=2/INVALIDARGUMENT
May 31 18:57:18 matta-slurm-control-0.novalocal systemd[1]: prometheus-slurm-exporter.service: Failed with result 'exit-code'.

Which is fixed in 0.21.

[JohnGarbutt]

nice.

[JohnGarbutt]

nice.

[sd109]

LGTM

[sjpb]

@m-bull does this also fix #187?

[m-bull]

Yeah - discussion here: vpenso/prometheus-slurm-exporter#67, with this fix from the development branch.