Fixes:
http://autobuild.buildroot.net/results/16c/16cba783be11cc5024f9c56bb0a7abb0acf13ef8/
The configure script of libxcrypt needs the open perl module on the host:
Can't locate open.pm in @INC (you may need to install the open module) (@INC
contains: /home/buildroot/autobuild/instance-2/output-1/host/lib/perl
/usr/local/lib64/perl5/5.36 /usr/local/share/perl5/5.36
/usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5
/usr/share/perl5) at ./build-aux/scripts/expand-selected-hashes line 20.
So add a check for it in dependencies.sh similar to how it is done for mpv.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>