fix formatting CIRCLE_TAG when building docs (#67026)
Summary:
Similar to pytorch/text#1416
malfet, brianjo
The previous code failed when tags changed from `v0.9.0` to `v0.10.0`. I tested this offline, it would be nice to somehow be actually tag the repo and see that this adds the correct documentation directory to the pytorch/pytorch.github.io repo.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67026
Reviewed By: saketh-are
Differential Revision: D31843381
Pulled By: malfet
fbshipit-source-id: 21526ad9ed4c1751c2d7f6d621da305f166a7f55
