Update: github actions runner image

Author: viest

.github/workflows/main.yml

@@ -8,18 +8,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [ubuntu-latest]
-        php-versions: ['8.0', '8.1', '8.2']
-        include:
-          - operating-system: 'ubuntu-18.04'
-            php-versions: '7.0'
-          - operating-system: 'ubuntu-18.04'
-            php-versions: '7.1'
-          - operating-system: 'ubuntu-18.04'
-            php-versions: '7.2'
-          - operating-system: 'ubuntu-18.04'
-            php-versions: '7.3'
-          - operating-system: 'ubuntu-18.04'
-            php-versions: '7.4'
+        php-versions: ['7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2']
     name: PHP ${{ matrix.php-versions }} Test on ${{ matrix.operating-system }}
     steps:
       - name: Checkout