Default --yes to true in CI

[ecraig12345]

The point of automated publishing is that it's...automated, so it's a bit silly to require people to manually pass -y or --yes when publishing in a CI context (and the failure mode tends to be bad/non-obvious as described in #812).

This PR changes the default of the yes option to true if CI (most platforms) or TF_BUILD (ADO) is set. Checks for other platforms' variables could be added if needed, but I looked at the docs for some other major platforms and all the ones I found set CI.

This could potentially be considered a breaking change, but yes is only used during publishing, and I'm not sure how anyone could be doing automated publishing without this option already set, so it's probably okay. (Also easily mitigated by setting to false manually.)

Fixes #812