Make openvsx publish optional

Author: jneira

.github/workflows/build.yml

@@ -13,12 +13,13 @@ jobs:
         with:
           node-version: 12
       - run: npm ci
-      - name: Publish to Open VSX Registry
-        uses: HaaLeo/publish-vscode-extension@v0
-        with:
-          pat: ${{ secrets.OPEN_VSX_TOKEN }}
       - name: Publish to Visual Studio Marketplace
         uses: HaaLeo/publish-vscode-extension@v0
         with:
           pat: ${{ secrets.VS_MARKETPLACE_TOKEN }}
           registryUrl: https://marketplace.visualstudio.com
+      - name: Publish to Open VSX Registry
+        continue-on-error: true
+        uses: HaaLeo/publish-vscode-extension@v0
+        with:
+          pat: ${{ secrets.OPEN_VSX_TOKEN }}