Revert "chore: Migrate workflows to Blacksmith (#34)"

This reverts commit 10db7d5833.

.github/workflows/docker.yml

@@ -8,7 +8,7 @@ on:
 jobs:
   push_to_registry:
     name: Push Docker image to Docker Hub
-    runs-on: blacksmith-2vcpu-ubuntu-2204
+    runs-on: ubuntu-latest
     steps:
       - name: Check out the repo
         uses: actions/checkout@v3