Add testing Perl versions.

Author: sekia

.github/workflows/ci.yml

@@ -16,6 +16,8 @@ jobs:
           - "5.32"
           - "5.34"
           - "5.36"
+          - "5.38"
+          - "5.40"
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2