Replace deprecated ::set-output with $GITHUB_OUTPUT (actions#2679)

Author: jongwooo

.github/workflows/arc-publish-chart.yaml

@@ -70,7 +70,7 @@ jobs:
       run: |
         changed=$(ct list-changed --config charts/.ci/ct-config.yaml)
         if [[ -n "$changed" ]]; then
-          echo "::set-output name=changed::true"
+          echo "changed=true" >> $GITHUB_OUTPUT
         fi
 
     - name: Run chart-testing (lint)

.github/workflows/arc-validate-chart.yaml

@@ -79,7 +79,7 @@ jobs:
         run: |
           changed=$(ct list-changed --config charts/.ci/ct-config.yaml)
           if [[ -n "$changed" ]]; then
-            echo "::set-output name=changed::true"
+            echo "changed=true" >> $GITHUB_OUTPUT
           fi
 
       - name: Run chart-testing (lint)

.github/workflows/gha-validate-chart.yaml

@@ -76,7 +76,7 @@ jobs:
           ct version
           changed=$(ct list-changed --config charts/.ci/ct-config-gha.yaml)
           if [[ -n "$changed" ]]; then
-            echo "::set-output name=changed::true"
+            echo "changed=true" >> $GITHUB_OUTPUT
           fi
 
       - name: Run chart-testing (lint)