Bring back version checking to Bittensor

[ibraheem-opentensor]

Is your feature request related to a problem? Please describe.

We used to have version checking prior to 8.0 - we should bring it back.

Describe the solution you'd like

Ideally we should check at the start if a newer version is available and prompt users accordingly

Describe alternatives you've considered

No response

Additional context

No response

[thewhaleking]

Should we do this for bittensor or for btcli? I think btcli makes more sense, and is more inline with normal situations. I don't think I've ever seen a library that wants me to update.