ci(publish): explicitly install node 20

OVSX requires Node 20, so we'll explicitly require Node 20 in the workflow instead of relying on the pre-installed one.

Author: nhedger

.github/workflows/~publish-to-ovsx-registry.yaml

@@ -18,6 +18,10 @@ jobs:
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         with:
           name: biome.vsix
+      - name: Setup Node
+        uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af # v4
+        with:
+          node-version: 20
       - name: Setup PNPM
         uses: pnpm/action-setup@v4
         with:

.github/workflows/~publish-to-vs-marketplace.yaml

@@ -19,6 +19,10 @@ jobs:
         uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
         with:
           name: biome.vsix
+      - name: Setup Node
+        uses: actions/setup-node@39370e3970a6d050c480ffad4ff0ed4d3fdee5af # v4
+        with:
+          node-version: 20
       - name: Setup PNPM
         uses: pnpm/action-setup@v4
         with: