ci: run ghcr publish on workflow_dispatch

Author: igboyes

.github/workflows/ci.yml

@@ -49,7 +49,10 @@ jobs:
         run: npx semantic-release
   ghcr:
     runs-on: ubuntu-24.04
-    if: github.repository_owner == 'Virtool' && github.event_name == 'push' && needs.release.outputs.git-tag != ''
+    if: |
+      github.repository_owner == 'Virtool' &&
+      (github.event_name == 'push' || github.event_name == 'workflow_dispatch') &&
+      needs.release.outputs.git-tag != ''
     needs: [release]
     steps:
     - name: Checkout