enable use of PHP 8.2

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: ['7.3', '7.4', '8.0', '8.1']
+        php-versions: ['7.3', '7.4', '8.0', '8.1', '8.2']
     name: PHP ${{ matrix.php-versions }} unit tests on ${{ matrix.operating-system }}
     env:
       extensions: gd, sqlite3
@@ -118,4 +118,3 @@ jobs:
     - name: Run unit tests
       run: npm test
       working-directory: js
-