fix: pass authentication header only if specified

action.yml

@@ -42,9 +42,13 @@ runs:
         # in order to increase the limit of 60 requests per hour per IP address to a higher value that's also counted
         # per GitHub account.
         # Caching is disabled in order not to receive stale responses from Varnish cache fronting GitHub API.
+        RELEASE_HEADER=''
+        if [ ! -z "${{github.token}}" ]; then
+          RELEASE_HEADER="--header 'authorization: Bearer ${{ github.token }}'"
+        fi
         RELEASE_INFO="$(curl --silent --show-error --fail \
-          --header 'authorization: Bearer ${{ github.token }}' \
           --header 'Cache-Control: no-cache, must-revalidate' \
+          ${RELEASE_HEADER} \
           "${RELEASE_URL}")"
         RELEASE_NAME="$(echo "${RELEASE_INFO}" | jq --raw-output ".name")"
         LOCATION="$(echo "${RELEASE_INFO}" \