bump nodejs version to 20

octokit dropped support for nodejs 16 and nodejs 20 is currently the only
version that is currently documented as supported [1].

[1] https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#runsusing-for-javascript-actions

Signed-off-by: Matthias Aßhauer <[email protected]>

Author: rimrul

action.yml

@@ -41,6 +41,6 @@ inputs:
       [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
     default: ${{ github.token }}
 runs:
-  using: 'node16'
+  using: 'node20'
   main: 'dist/index.js'
   post: 'dist/index.js'