Use docker.io CLI-only, ignore sync file changes

.forgejo/workflows/build.yaml

@@ -3,6 +3,10 @@ name: Build ts6-viewer
 on:
   push:
     branches: [main]
+    paths-ignore:
+      - '.forgejo/workflows/sync.yaml'
+      - '.forgejo/trigger'
+  workflow_dispatch:
 
 jobs:
   build:
@@ -12,7 +16,7 @@ jobs:
         run: git clone --depth 1 https://git.joshuahirsig.xyz/docker/ts6-viewer.git .
 
       - name: Install Docker CLI
-        run: curl -fsSL https://get.docker.com | sh
+        run: apt-get update -qq && apt-get install -y -qq docker.io >/dev/null
 
       - name: Build and push
         run: |