ci: improve coverage report (api-platform#6085)

* test: remove nullable return type as it can't happen

* ci: uploads individual component coverage reports

Author: aegypius

.github/workflows/ci.yml

@@ -202,6 +202,14 @@ jobs:
           - RamseyUuid
           - GraphQl
           - Serializer
+          - Symfony
+        include:
+          - php: '8.1'
+            coverage: true
+          - php: '8.2'
+            coverage: true
+          - php: '8.3'
+            coverage: true
       fail-fast: false
     steps:
       - name: Checkout

phpunit.xml.dist

@@ -29,6 +29,7 @@
             <directory>features</directory>
             <directory>tests</directory>
             <directory>vendor</directory>
+            <directory>src/**/Tests/</directory>
             <file>.php-cs-fixer.dist.php</file>
         </exclude>
     </coverage>