fix(ci): add GH_TOKEN to release workflow for draft release creation (#44)

## Summary

Fixes the release workflow failure where the "Create draft release with
notes" step was failing with exit code 4.

**Problem:** The `gh release create` command requires authentication via
the `GH_TOKEN` or `GITHUB_TOKEN` environment variable. While the
workflow declares `permissions: contents: write` at the job level, the
gh CLI still requires the token to be explicitly passed.

**Solution:** Add `GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}` to the
environment for the draft release creation step.

**Related:**
https://github.com/pinecone-io/pinecone-mcp/actions/runs/21404698668/job/61625174745

## Test plan

- [ ] Merge this PR
- [ ] Run the release workflow manually to verify the draft release is
created successfully

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Ensures the `gh release create` step in the release workflow
authenticates properly.
> 
> - Adds `env: GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}` to the `Create
draft release with notes (prod)` step in `.github/workflows/release.yml`
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
2df11af. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: jhamon

.github/workflows/release.yml

@@ -122,6 +122,8 @@ jobs:
       - name: Create draft release with notes (prod)
         if: github.event.inputs.releaseMode == 'prod'
         shell: bash
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           gh release create "v${{ steps.version-bump-prod.outputs.version }}" \
             --draft \