Add php 8.1 to test matrix

Author: othercorey

.github/workflows/ci.yml

@@ -15,10 +15,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: ['7.2', '7.4', '8.0']
+        php-version: ['7.2', '8.0']
         db-type: [mysql, pgsql, sqlite]
         prefer-lowest: ['']
         include:
+          - php-version: '8.1'
+            db-type: 'sqlite'
           - php-version: '7.2'
             db-type: 'sqlite'
             prefer-lowest: 'prefer-lowest'
@@ -63,12 +65,12 @@ jobs:
 
     - name: Composer install
       run: |
-        if [[ ${{ matrix.php-version }} == '8.0' ]]; then
-          composer install --ignore-platform-reqs
-        elif ${{ matrix.prefer-lowest == 'prefer-lowest' }}; then
+        if ${{ matrix.prefer-lowest == 'prefer-lowest' }}; then
           composer update --prefer-lowest --prefer-stable
+        elif ${{ matrix.php-version == '8.1' }}; then
+          composer update --ignore-platform-reqs
         else
-          composer install
+          composer update
         fi
 
     - name: Run PHPUnit