Use Ubuntu 24 and prepare workflow for merging

Author: agarciadom

.github/workflows/push-docker-image.yml

@@ -2,15 +2,15 @@ name: Push Docker Image
 
 on:
   push:
-    branches: [ "micronaut" ]
+    branches: [ "main", "micronaut" ]
 
 env:
   REGISTRY: ghcr.io
   IMAGE_NAME: ${{ github.repository }}
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     permissions:
       contents: read
       packages: write