delete the GitHub-hosted workflows the native gate replaces

ci.yml ran static checks and the Go suite on ubuntu-latest; docs.yml built
docs/ and pushed it to GitHub Pages from two more ubuntu jobs. The suite now
runs in hanzo.yml on the git.hanzo.ai fleet. Nothing is lost with Pages: the
site was never enabled, so those uploads had no destination — when docs get a
home it is the static plane, declared here as site:.

.github/workflows/docs.yml

@@ -1,66 +0,0 @@
-name: Deploy Docs to GitHub Pages
-
-on:
-  push:
-    branches: [main, master]
-    paths:
-      - 'docs/**'
-      - '*.go'
-      - 'README.md'
-  workflow_dispatch:
-
-permissions:
-  contents: read
-  pages: write
-  id-token: write
-
-concurrency:
-  group: pages
-  cancel-in-progress: false
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    defaults:
-      run:
-        working-directory: docs
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Setup pnpm
-        uses: pnpm/action-setup@v4
-        with:
-          version: 10
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: '22'
-          cache: 'pnpm'
-          cache-dependency-path: docs/pnpm-lock.yaml
-
-      - name: Install dependencies
-        run: pnpm install --frozen-lockfile
-
-      - name: Build docs
-        run: pnpm build
-
-      - name: Setup Pages
-        uses: actions/configure-pages@v5
-
-      - name: Upload artifact
-        uses: actions/upload-pages-artifact@v3
-        with:
-          path: docs/out
-
-  deploy:
-    environment:
-      name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
-    runs-on: ubuntu-latest
-    needs: build
-    steps:
-      - name: Deploy to GitHub Pages
-        id: deployment
-        uses: actions/deploy-pages@v4