add CI for Perl 5.42 - #551

Author: mohawk2

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        perl-version: ['5.16.0']
+        perl-version: ['5.16.0', '5.42']
         perl-threaded: [false]
         include:
           - perl-version: '5.30'