[python-committers] Labels on GitHub now have classification prefixes

https://github.com/python/cpython/labels now have prefixes for all labels to make it easier to find the relevant labels for some kind of classification. For instance, all the labels for the type of PR -- e.g. bugfix, enhancement, etc. -- now all have a "type-" prefix so you know what your options are (adding more labels is also always an option). This also makes it easier to tell which PRs are lacking possible labels for each classification (e.g. which PRs don't have a "type" label yet).