ci: limit to opencode repo

.github/workflows/docs-update.yml

@@ -8,7 +8,8 @@ on:
 
 jobs:
   update-docs:
-    runs-on: ubuntu-latest
+    if: github.repository == 'sst/opencode'
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     permissions:
       id-token: write
       contents: write
@@ -19,6 +20,9 @@ jobs:
         with:
           fetch-depth: 0 # Fetch full history to access commits
 
+      - name: Setup Bun
+        uses: ./.github/actions/setup-bun
+
       - name: Get recent commits
         id: commits
         run: |