ci: do not use set-output in actions

Author: pl-github

.github/workflows/code_coverage.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Load dependencies from cache
         id: composer-cache
         run: |
-          echo "::set-output name=dir::$(composer config cache-files-dir)"
+          echo "{dir}={$(composer config cache-files-dir)}" >> $GITHUB_OUTPUT
       - uses: actions/cache@v4
         with:
           path: ${{ steps.composer-cache.outputs.dir }}