tag: use filtered repo when creating new tags (issue5539) When pruning a changeset that added a tag and then adding another tag, the "pruned" tag gets restored. This is because the tag creation step (tags._tag() call in tags.tag()) is currently done on the unfiltered repo. This behavior has been there from 7977d35df13b which backs out b08af8f0ac01 with no clear reason but caution on unthought situations at that time. In this changeset, we pass the filtered repo to tags._tag(), preventing "pruned" tags to reappear. This somehow restores b08af8f0ac01, though now we arguably have a valid use case for.