Versioning tags in metrics was removed from v0.34 to v0.38

[cmwaters]

v0.34.x

https://github.com/celestiaorg/celestia-core/blob/b3e1e44e8dc3fbf714d208e5120ffc0bfdfade5b/node/node.go#L882

v0.38.x

https://github.com/celestiaorg/celestia-core/blob/bf3ae981ab6d04cd1f21224c731394c4198869d7/node/node.go#L318

We also had this comment from Staking Facilities

Hey guys, since version 4, I noticed that the version information was removed from the exported Prometheus metrics. I totally understand that including it in every single metric was excessive, but having at least one dedicated metric that exposes the current version was actually really useful on our end. Would it be possible to consider reintroducing a single version metric in a future release?

We don't have to have the software version on every metric but I do agree it would be helpful (also for our devops team) if we included the metric somewhere