fix(ci): increase docker build timeout to 60 minutes (#7)

Multi-platform builds with QEMU ARM emulation exceed 30 minutes
for this multi-stage Dockerfile (Ruby gems + Node compilation).

Co-authored-by: Sebastian Noe <sebastian.schneider@boxine.de>

.github/workflows/docker-publish.yml

@@ -10,7 +10,7 @@ permissions: {}
 jobs:
   build-and-push:
     runs-on: ubuntu-latest
-    timeout-minutes: 30
+    timeout-minutes: 60
     permissions:
       contents: read
       packages: write