pkgtools/pkglint: update to 19.4.8

Changes since 19.4.7:

The diagnostic for homepages using FTP is simpler now.

When running pkglint recursively on the top-level directory, the
inter-package checks (distfile hashes, unused licenses) are enabled
implicitly. This way, the only effect of the -Cglobal option is now
whether the pkgsrc infrastructure files are checked as well.

The check for removed packages that have not been recorded in
doc/CHANGES prints the correct lines when pkglint is run with the
--source option.

Fatal technical errors are no longer treated as diagnostics since they
are none. That was an early conceptual mistake, but since these fatal
error didn't happen often, it didn't matter.

In diagnostics, when referring to other lines, the previously used words
before/after have been replaced with above/below to avoid any confusion
whether space or time is meant.

In CONF_FILES, spaces and quotes are allowed.
See https://gnats.netbsd.org/42191.

Fixed unintended side-effects when running pkglint --autofix --only.
Before, all fixes were applied to the file, whether or not they matched
the --only option.

Fixed resolution of relative paths of the form ../../category/package
when they appeared in an infrastructure file.

Lots of refactorings and housekeeping, as usual.

(rillig)