Use shivammathur/setup-php for GitHub Actions tests to allow more PHP…

… versions than what's installed on ubuntu-latest which is just 8.1 at the moment

- actions/runner-images#6399
- actions/runner-images#6331

.github/workflows/tests.yml

@@ -12,7 +12,10 @@ jobs:
     steps:
     - name: OS info
       run: cat /etc/os-release
-    - run: sudo update-alternatives --set php /usr/bin/php${{ matrix.php-version }}
+    - uses: shivammathur/setup-php@v2
+      with:
+        coverage: none
+        php-version: ${{ matrix.php-version }}
     - name: PHP info
       run: |
         php -v
@@ -26,7 +29,10 @@ jobs:
           - "8.1"
     steps:
     - uses: actions/checkout@v2
-    - run: sudo update-alternatives --set php /usr/bin/php${{ matrix.php-version }}
+    - uses: shivammathur/setup-php@v2
+      with:
+        coverage: none
+        php-version: ${{ matrix.php-version }}
     - run: find -name *.php -exec php -l {} \; 2>&1 1>/dev/null | if grep "^.*error:"; then exit 1; else exit 0; fi
 
   test:
@@ -37,5 +43,8 @@ jobs:
           - "8.1"
     steps:
     - uses: actions/checkout@v2
-    - run: sudo update-alternatives --set php /usr/bin/php${{ matrix.php-version }}
+    - uses: shivammathur/setup-php@v2
+      with:
+        coverage: none
+        php-version: ${{ matrix.php-version }}
     - run: php site/tests/test.php