Remove broken changelog generation step from auto-release workflow

The gscli functionality has been removed from the codebase, but the
auto-release workflow was still trying to run:
uv run python src/codegen/gscli/cli.py generate changelog

This was causing deployment failures. Since the gscli stuff is no
longer needed, removing the entire generate-changelog job.

Fixes CG-18853

Author: codegen-sh[bot]

.github/workflows/auto-release.yml

@@ -35,39 +35,7 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
-  generate-changelog:
-    if: ${{ needs.semantic-version.outputs.release-tag }}
-    needs: semantic-version
-    name: Generate Changelog
-    runs-on: ubuntu-latest
-    environment: auto-release
-    permissions:
-      contents: write
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-          token: ${{ secrets.GHA_TOKEN }}
 
-      - name: Setup backend
-        uses: ./.github/actions/setup-environment
-
-      - name: Generate changelog
-        env:
-          OPEN_AI_TOKEN: ${{ secrets.OPEN_AI_TOKEN }}
-        run: uv run python src/codegen/gscli/cli.py generate changelog --openai-key ${{ secrets.OPEN_AI_TOKEN }}
-
-      - name: Commit changes
-        run: |
-          git config --local user.email "github-actions[bot]@users.noreply.github.com"
-          git config --local user.name "github-actions[bot]"
-          git add docs/changelog/changelog.mdx
-          git diff --staged --quiet || git commit -m "update changelog"
-
-      - name: Push changes
-        uses: ad-m/github-push-action@master
-        with:
-          branch: ${{ github.ref }}
 
   release:
     if: ${{ needs.semantic-version.outputs.release-tag }}