fix: correctly pipe filters in jq invocation (#330)

Author: sd2k

.github/workflows/docker.yml

@@ -84,8 +84,7 @@ jobs:
           # (note the image tag does not include the "v" prefix)
           jq --arg version "${{ steps.version.outputs.VERSION }}" \
             --arg image "docker.io/grafana/mcp-grafana:${{ steps.image-tag.outputs.IMAGE_TAG }}" \
-             '.version = $version' \
-             '.packages[0].identifier = $image' server.json > server.json.tmp
+             '.version = $version | .packages[0].identifier = $image' server.json > server.json.tmp
           mv server.json.tmp server.json
 
       - name: Login to MCP Registry