Further cross-building problems with chatty

[Travis Wrightsman <travis@wrightsman.org>]

Dear Debian cross-builders,

After fixing #996699, the libpurple0 dependency for chatty resolves
correctly during cross-building. Unfortunately this seems to have
uncovered further issues down the dependency chain. I'm now getting the
following error while attempting to cross-build chatty with pbuilder:

The following packages have unmet dependencies:
 libpurple0:arm64 : Depends: pidgin-data:arm64 (< 2.14.8-z) but it is not installable
                    Depends: pidgin-data:arm64 (>= 2.14.8) but it is not installable
                    Depends: perl-base:arm64 but it is not installable
                    Depends: perlapi-5.32.1:arm64
E: Unable to correct problems, you have held broken packages.
E: pbuilder-satisfydepends failed.

I believe #828759 relates to this for pidgin-data and #717882 for
perl-base and perlapi.

I'm not sure on the correct fixes for these packages. It looks like the
perl bug is especially tricky?

Any advice would be much appreciated.

Best,
Travis