D3825: grep: deprecates `--all` flag

[Yuya Nishihara]

>  @command('grep',
>      [('0', 'print0', None, _('end fields with NUL')),
> -    ('', 'all', None, _('print all revisions that match')),
> +    ('', 'all', None, _('print all revisions that match (DEPRECATED)')),
>      ('', 'diff', None, _('print all revisions when the term was introduced or removed')),

This doesn't apply. Can you rebase onto the current tip?