Fix update-link-index-action (#248)

The action failed in
https://github.com/elastic/kibana.md/actions/runs/12796978373/job/35677871586

This should fix it.

Author: reakaleek

actions/update-link-index/action.yml

@@ -24,9 +24,6 @@ inputs:
 runs:
   using: composite
   steps:
-    - name: Update Link Index
-      run: |
-        echo "Updating link index"
     - name: Generate AWS Role ARN
       id: role_arn
       shell: python
@@ -50,7 +47,9 @@ runs:
         role-to-assume: ${{ steps.role_arn.outputs.result }}
         aws-region: us-east-1
     - name: Upload Link Reference File to S3
-      bash: shell
+      shell: bash
+      env:
+        LINK_REFERENCE_FILE: ${{ inputs.link_reference_file }}
       run: |
         repository_name=$(basename "${GITHUB_REPOSITORY}")
-        aws s3 cp ${{ inputs.link_reference_file }} "s3://${{ inputs.aws_s3_bucket_name }}/${repository_name}.json"
+        aws s3 cp "${LINK_REFERENCE_FILE}" "s3://${{ inputs.aws_s3_bucket_name }}/${repository_name}.json"