build: Drop Perl dependency on autotools
We don’t have the same dependency in the Meson build, and we don’t depend on Perl any more. See #1332. The last remaining Perl script, gen-unicode-tables.pl, is only ever run manually when we update our Unicode character database. It will be ported to Python in due course.
Signed-off-by: Philip Withnall withnall@endlessm.com
Closes #1332