Enable autotag feature w/ wandb

[vwxyzjn]

This PR automatically tags the wandb experiments with the git tags and PR number if possible.

The tag will be helpful later on for RLops for which we compare the performance of some sanity check tasks between different. versions of the library.

[vwxyzjn]

I put the feature in PPOConfig which might not be the best place... Would you recommend putting it anywhere else? We just need to run the tagging feature before wandb.init

[younesbelkada]

This looks great to me ! Amazing feature 🚀
I think placing it on the PPOConfig is good, I think we should remove the prints (and ideally replace them with a warnings or logging.info message but it can be done later I think) wdyt?

[vwxyzjn]

@younesbelkada thanks for the review! I have put them under logging.info.

[younesbelkada]

Awesome feature! Thanks a lot for adding this @vwxyzjn ! 🎉
Left one suggestion, otherwise LGTM

[younesbelkada]

Sorry this should fix the failing CI !