only deploy from duckdb repo (#6)

Author: jraymakers

.github/workflows/MainDistributionPipeline.yml

@@ -46,7 +46,7 @@ jobs:
       extension_name: ui
 
   duckdb-stable-deploy:
-    if: ${{ startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main' }}
+    if: ${{ github.repository == 'duckdb/duckdb-ui' && ( startsWith(github.ref, 'refs/tags/v') || github.ref == 'refs/heads/main' ) }}
     name: Deploy stable extension binaries
     needs: duckdb-stable-build
     uses: duckdb/extension-ci-tools/.github/workflows/[email protected]