add CI jobs for Symfony 7.3

Author: xabbuh

.github/workflows/ci.yaml

@@ -69,6 +69,9 @@ jobs:
           - php-version: '8.2'
             composer-options: '--prefer-stable'
             symfony-version: '7.2.*'
+          - php-version: '8.2'
+            composer-options: '--prefer-stable'
+            symfony-version: '7.3.*'
           - php-version: '8.3'
             composer-options: '--prefer-stable'
             symfony-version: '6.4.*'
@@ -78,6 +81,9 @@ jobs:
           - php-version: '8.3'
             composer-options: '--prefer-stable'
             symfony-version: '7.2.*'
+          - php-version: '8.3'
+            composer-options: '--prefer-stable'
+            symfony-version: '7.3.*'
           - php-version: '8.4'
             composer-options: '--prefer-stable'
             symfony-version: '6.4.*'
@@ -87,6 +93,9 @@ jobs:
           - php-version: '8.4'
             composer-options: '--prefer-stable'
             symfony-version: '7.2.*'
+          - php-version: '8.4'
+            composer-options: '--prefer-stable'
+            symfony-version: '7.3.*'
 
     steps:
       - name: 'Check out'