Enable CI for 8.2

Was waiting for php-cs-fixer to have official 8.2 support but that's
been a while coming so we'll just have it run while ignoring the env
mismatch for now. We don't use any 8.2 features so it shouldn't be
an issue.

.github/workflows/main.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-20.04
     strategy:
       matrix:
-        php-versions: ['7.4', '8.0', '8.1']
+        php-versions: ['7.4', '8.0', '8.1', '8.2']
       fail-fast: false
     steps:
     - name: Checkout
@@ -80,3 +80,5 @@ jobs:
         
     - name: Run tests
       run: npx gulp test --continue
+      env:
+        PHP_CS_FIXER_IGNORE_ENV: 1