Test parallel only on 8.3 nightly

8.1 and 8.2 segfault until the next patch release.

.github/workflows/ci.yml

@@ -11,13 +11,21 @@ jobs:
         include:
           - operating-system: 'ubuntu-latest'
             php-version: '8.1'
+            php-ts: nts
 
           - operating-system: 'ubuntu-latest'
             php-version: '8.2'
+            php-ts: nts
+
+          - operating-system: 'ubuntu-latest'
+            php-version: '8.3'
+            php-extensions: parallel
+            php-ts: ts
 
           - operating-system: 'macos-latest'
             php-version: '8.2'
             job-description: 'on macOS'
+            php-ts: nts
 
     name: PHP ${{ matrix.php-version }} ${{ matrix.job-description }}
 
@@ -36,9 +44,9 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php-version }}
-          extensions: parallel
+          extensions: ${{ matrix.php-extensions }}
         env:
-          phpts: ts
+          phpts: ${{ matrix.php-ts }}
           fail-fast: true
 
       - name: Get Composer cache directory