fix print outputs step (#859)

Author: Iván Reinoso García

.github/workflows/stale.yml

@@ -16,4 +16,4 @@ jobs:
           days-before-close: 5
           exempt-issue-labels: 'blocked,must,should,keep'
       - name: Print outputs
-        run: echo ${{ join(steps.stale.outputs.*, ',') }}
+        run: echo ${{ format('{0},{1}', toJSON(steps.stale.outputs.staled-issues-prs), toJSON(steps.stale.outputs.closed-issues-prs)) }}

.github/workflows/test.yml

@@ -25,4 +25,4 @@ jobs:
           stale-pr-message: 'This PR is stale'
           debug-only: true
       - name: Print outputs
-        run: echo ${{ join(steps.stale.outputs.*, ',') }}
+        run: echo ${{ format('{0},{1}', toJSON(steps.stale.outputs.staled-issues-prs), toJSON(steps.stale.outputs.closed-issues-prs)) }}