Update action.yml

Author: balakrishna-deriv

.github/actions/checkout/action.yml

@@ -43,13 +43,13 @@ runs:
               if git ls-remote --heads --quiet --exit-code https://${{ inputs.token }}@github.com/${{ inputs.repository }}.git ${{ inputs.ref }}
               then
                 echo "::notice::Checkout: ${{ inputs.repository }} using ${{ inputs.ref }}"
-                echo "ref-exists=true" >> $GITHUB_OUTPUT
+                echo "::set-output name=ref-exists::true"  # Use ::set-output for boolean output
               else
                 echo "::notice::Checkout: ${{ inputs.repository }} does not have ref ${{ inputs.ref }} (fallback to ${{ inputs.alternate_ref }})"
-                echo "ref-exists=false" >> $GITHUB_OUTPUT
+                echo "::set-output name=ref-exists::false"  # Use ::set-output for boolean output
               fi
 
-        - if: steps.repo.outputs.ref-exists == 'true'
+        - if: steps.repo.outputs.ref-exists
           uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
           with:
               fetch-depth: ${{ inputs.fetch-depth }}
@@ -58,7 +58,7 @@ runs:
               ref: ${{ inputs.ref }}
               token: ${{ inputs.token }}
 
-        - if: steps.repo.outputs.ref-exists == 'false'
+        - if: !steps.repo.outputs.ref-exists  # Use ! for negation
           uses: actions/checkout@a12a3943b4bdde767164f792f33f40b04645d846
           with:
               fetch-depth: ${{ inputs.fetch-depth }}