fix: add bun setup to release workflow

make release depends on vscode-ext which requires bun to build
the VS Code extension. The release workflow was missing the bun
setup step, causing the Build release binaries step to fail.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

.github/workflows/release.yml

@@ -18,6 +18,7 @@ jobs:
       - uses: actions/setup-go@v6
         with:
           go-version: '1.26'
+      - uses: oven-sh/setup-bun@v2
       - name: Build release binaries
         run: make release
       - name: Create GitHub Release