#!/usr/bin/perl ######################################
# Check installed CPAN modules for use of "use vars" #
# Because Perl 5.28.0 removes discouraged "use vars" #
# https://perlmonks.org/index.pl?node_id=1217408     #
######################################################
[download]

I think you are misunderstanding the perldelta entry. It says (emphasis mine):

The usage of use vars has been discouraged since the introduction of our in Perl 5.6.0. Where possible the usage of this pragma has now been removed from the Perl source code.

vars is still very much present, just its usage by the Perl core has been removed. Note that the change is not listed in the "Incompatible Changes" section, and "Updated Modules and Pragmata" actually says "vars has been upgraded from version 1.03 to 1.04." See also:

perl5/ $ git log --oneline --grep="use vars" v5.26.0..v5.28.0
5069e57764 Update Filter::Util::Call to CPAN version 1.58
1218f5ba79 Remove use vars from B::Deparse
bc60657c80 configpm: fix duplicate 'our' declaration
d8f3f638c2 [MERGE] Remove unnecessary use of 'use vars'
9b78f2106b Document the removal of use vars from sources
e64a0c479a Replace multiple 'use vars' by 'our' in regen.
83461ff883 Replace multiple 'use vars' by 'our' in t
3d3a0a8a5e Replace multiple 'use vars' by 'our' in utils
fd55ca4fb1 Replace multiple 'use vars' by 'our' in ext
cc01160e81 Replace multiple 'use vars' by 'our' in lib
1a58b39af8 Replace multiple 'use vars' by 'our' in dist
94d11354c7 fix a benchmarks sprintf entry