shrink-revlog: make it work on windows (issue1976)

merge main with stable

merge crew together

merge stable together

merge with stable

shrink-revlog: avoid cryptic error when used as an extension When shrink-revlog is used as an extension, it would produce an error when switching back to stable because the script will try to execute itself.

transaction: initialize self.journal to None after deletion This avoid a warning when having an empty transaction, where hg would try to delete the journal twice.