add correct headers for previews (#8)

Co-authored-by: lukqw <lukqw@users.noreply.github.com>

Author: lukqw

preview/action.yml

@@ -35,6 +35,7 @@ runs:
         previewName=preview-$prId
 
         response=$(curl -X POST -d '{}' \
+            -H 'ls-api-key: ${{ inputs.localstack-api-key }}' \
             -H 'authorization: token ${{ inputs.localstack-api-key }}' \
             -H 'content-type: application/json' \
             https://api.localstack.cloud/v1/previews/$previewName)