minor #110 add CI job for Symfony 5.3 (xabbuh)

This PR was merged into the 0.1-dev branch.

Discussion
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add CI job for Symfony 5.3

Commits
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3fbf46e add CI job for Symfony 5.3

Author: xabbuh

.github/workflows/ci.yaml

@@ -108,6 +108,9 @@ jobs:
           - php-version: '7.4'
             composer-options: '--prefer-stable'
             symfony-version: '5.2.*'
+          - php-version: '7.4'
+            composer-options: '--prefer-stable'
+            symfony-version: '5.3.*'
           - php-version: '8.0'
 
     steps: