codecov.yml in pdd-0.21.3

- old
+ new

@@ -4,10 +4,10 @@
   push:
     branches:
       - master
 jobs:
   codecov:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-ruby@v1
         with:
           ruby-version: 2.7