Add skipDuplicate to Open VSX publish step (#3104)

Makes it possible to rerun the deploy workflow when the vscode market
place failed previously

Author: AndreasArvidsson

.github/workflows/deploy.yaml

@@ -47,6 +47,7 @@ jobs:
         with:
           pat: ${{ secrets.OPEN_VSX_TOKEN }}
           packagePath: packages/cursorless-vscode/dist
+          skipDuplicate: true
 
       - name: Publish to Visual Studio Marketplace
         uses: HaaLeo/publish-vscode-extension@v2