[3.12] gh-129044: Update glossary entry for 'loader' to reflect current import system (#129073)#129130

AA-Turner merged 3 commits intopython:3.12python/cpython:3.12from

nikalinov:backport-e1fa2fc-3.12nikalinov/cpython:backport-e1fa2fc-3.12Copy head branch name to clipboard