Bump to github-script@v7

This gets rid of the obsolete node.js 16.

Author: martinpitt

action.yml

@@ -27,7 +27,7 @@ runs:
 
     - name: Publish release
       id: publish
-      uses: actions/github-script@v6
+      uses: actions/github-script@v7
       with:
         script: |
           const fs = require('fs');