try this

.github/workflows/test.yml

@@ -23,7 +23,7 @@ jobs:
     generate-tests:
         runs-on: ubuntu-latest
         outputs:
-            all_tests: ${{ env.all_tests }}
+            all_tests: ${{ steps.get_all_tests.outputs.all_tests }}
         steps:
             - name: Checkout code
               uses: actions/checkout@v4
@@ -34,9 +34,9 @@ jobs:
                   # Run the script and capture its output
                   output=$(./scripts/test.sh)
                   # Output the result in a way that GitHub Actions can read
-                  echo "all_tests=$output" >> $GITHUB_ENV
+                  echo "::set-output name=all_tests::$output"
             - name: Print the captured output
-              run: echo "${{ env.all_tests }}"
+              run: echo "${{ steps.get_all_tests.outputs.all_tests }}"
     debug-generate-tests:
         name: ${{matrix.tests}}
         needs: generate-tests