update symfony version in matrix

Author: teiling88

.github/workflows/php.yml

@@ -9,10 +9,10 @@ jobs:
         strategy:
             matrix:
                 php: ['8.0', '8.1', '8.2', '8.3', '8.4', '8.5']
-                symfony: ['^6.4', '^7.4', '^8.0']
+                symfony: ['6.4.29', '7.4', '8.0']
                 exclude:
                   - php: 8.0
-                    symfony: 6.4
+                    symfony: 6.4.29
                   - php: 8.0
                     symfony: 7.0
                   - php: 8.1