Update publish.yml

Author: neilime

.github/workflows/publish.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Setup PHP, with composer and extensions
         uses: shivammathur/setup-php@master #https://github.com/shivammathur/setup-php
         with:
-          php-version: 7.4
+          php-version: 8.0
           extensions: json
           coverage: pcov