What happens if you turn import into what's obviously a method call (if you already have an import symbol in your current package, you may have trouble) and use a named lexical?

use Symbol 'delete_package';

foreach my $module (@modules) {
   require "sub/$module.pm";
   $module->import(qw(foo bar));
   foo();
   bar();
   # cleanup
   delete_package($module);
}
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