minor #17121 Fix CI by reverting #17020 (HeahDude)

This PR was merged into the 4.4 branch.

Discussion
----------

Fix CI by reverting #17020

The CI is failing in #16992 because of this, see https://github.com/symfony/symfony-docs/runs/7704382531?check_suite_focus=true.

My guess if that it's now fixed upstream thanks to symfony-tools/symfony-application#14.

Commits
-------

7c7c76e fix CI by reverting #17020

Author: javiereguiluz

.github/workflows/ci.yaml

@@ -116,11 +116,6 @@ jobs:
             if: ${{ steps.find-files.outputs.files }}
             run: composer create-project symfony-tools/code-block-checker:@dev _checker
 
-          - name: Allow Flex
-            if: ${{ steps.find-files.outputs.files }}
-            run: |
-              composer config --no-plugins allow-plugins.symfony/flex true
-
           - name: Install test application
             if: ${{ steps.find-files.outputs.files }}
             run: |