chore - Don't build ubuntu image on PR

Author: raymyers

.github/workflows/ghcr-build.yml

@@ -40,9 +40,7 @@ jobs:
           # Only build nikolaik on PRs, otherwise build both nikolaik and ubuntu.
           if [[ "$GITHUB_EVENT_NAME" == "pull_request" ]]; then
             json=$(jq -n -c '[
-                { image: "nikolaik/python-nodejs:python3.12-nodejs22", tag: "nikolaik" },
-                { image: "ubuntu:24.04", tag: "ubuntu" }
-
+                { image: "nikolaik/python-nodejs:python3.12-nodejs22", tag: "nikolaik" }
               ]')
           else
             json=$(jq -n -c '[