fix(ci): use PACKAGES_TOKEN PAT for docker registry auth

The auto-injected GITEA_TOKEN does not have effective write access to
the container registry on Gitea 1.26 even with `permissions: packages:
write` set. Switching to a dedicated PAT (write:package scope) stored
as the PACKAGES_TOKEN repo secret.

Bumps version to 1.2.3 to trigger a fresh tag-build.

.gitea/workflows/docker-build.yml

@@ -18,7 +18,7 @@ jobs:
         with:
           registry: gitea.shcizo.se
           username: ${{ gitea.actor }}
-          password: ${{ secrets.GITEA_TOKEN }}
+          password: ${{ secrets.PACKAGES_TOKEN }}
 
       - uses: docker/metadata-action@v5
         id: meta