ci: remove nix build-and-commit workflow

No longer needed — activation is now built via setup.py
(pip install --no-build-isolation -e .) in training yamls.

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

.github/workflows/build-and-commit.yml

@@ -1,120 +0,0 @@
-name: Nix build and commit
-
-on:
-  pull_request:
-    types: [opened, synchronize, reopened]
-  workflow_dispatch:
-
-permissions:
-  contents: write
-
-jobs:
-  check-commit:
-    runs-on: ubuntu-latest
-    outputs:
-      skip: ${{ steps.check.outputs.skip }}
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - id: check
-        run: |
-          if [ "${{ github.event_name }}" = "pull_request" ]; then
-            msg=$(git log -1 --pretty=%B "${{ github.event.pull_request.head.sha }}")
-          else
-            msg="manual dispatch"
-          fi
-          echo "Commit message: $msg"
-          if echo "$msg" | grep -q '\[skip-build\]'; then
-            echo "skip=true" >> "$GITHUB_OUTPUT"
-          else
-            echo "skip=false" >> "$GITHUB_OUTPUT"
-          fi
-
-  build_and_commit:
-    needs: check-commit
-    if: needs.check-commit.outputs.skip == 'false'
-    runs-on: docker-builder-01
-    steps:
-      - name: Show disk usage
-        run: df -h
-
-      - name: Notify build start on Slack
-        id: slack_start
-        run: |
-          msg="*Build started* for \`${{ github.repository }}\`\nBranch: \`${{ github.ref_name }}\`\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Workflow>"
-          response=$(curl -s -X POST \
-            -H "Authorization: Bearer ${{ secrets.SLACK_TOKEN }}" \
-            -H "Content-type: application/json; charset=utf-8" \
-            --data "{\"channel\":\"${{ secrets.SLACK_CHANNEL_ID }}\",\"text\":\"$msg\"}" \
-            https://slack.com/api/chat.postMessage)
-          ts=$(echo "$response" | jq -r '.ts')
-          echo "thread_ts=$ts" >> "$GITHUB_OUTPUT"
-          echo "$response"
-
-      - name: Checkout repository
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-          lfs: true
-          ref: ${{ github.head_ref || github.ref }}
-
-      - name: Install Nix
-        uses: cachix/install-nix-action@v31
-
-      - name: Setup huggingface cachix
-        uses: cachix/cachix-action@v15
-        with:
-          name: huggingface
-
-      - name: Clean build directory
-        run: |
-          rm -rf build
-
-      - name: Build with Nix
-        run: |
-          nix run .#build-and-copy \
-              --override-input kernel-builder github:huggingface/kernel-builder \
-              --max-jobs 8 \
-              -j 8 \
-              -L
-
-      - name: List built binaries
-        run: |
-          ls build
-
-      - name: Commit build artifact
-        run: |
-          git config user.name "github-actions[bot]"
-          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
-          git add build/*
-          git commit -m "Add built binary [skip-build]"
-
-      - name: Push changes
-        run: |
-          git push origin HEAD:"$HEAD_REF"
-        env:
-          HEAD_REF: ${{ github.head_ref || github.ref }}
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Notify success on Slack (thread)
-        if: success()
-        run: |
-          ts="${{ steps.slack_start.outputs.thread_ts }}"
-          msg="*Build succeeded* for \`${{ github.repository }}\`\nBranch: \`${{ github.ref_name }}\`\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Workflow>"
-          curl -s -X POST \
-            -H "Authorization: Bearer ${{ secrets.SLACK_TOKEN }}" \
-            -H "Content-type: application/json; charset=utf-8" \
-            --data "{\"channel\":\"${{ secrets.SLACK_CHANNEL_ID }}\",\"text\":\"$msg\",\"thread_ts\":\"$ts\"}" \
-            https://slack.com/api/chat.postMessage
-
-      - name: Notify failure on Slack (thread)
-        if: failure()
-        run: |
-          ts="${{ steps.slack_start.outputs.thread_ts }}"
-          msg="*Build failed* for \`${{ github.repository }}\`\nBranch: \`${{ github.ref_name }}\`\n<${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}|View Workflow>"
-          curl -s -X POST \
-            -H "Authorization: Bearer ${{ secrets.SLACK_TOKEN }}" \
-            -H "Content-type: application/json; charset=utf-8" \
-            --data "{\"channel\":\"${{ secrets.SLACK_CHANNEL_ID }}\",\"text\":\"$msg\",\"thread_ts\":\"$ts\"}" \
-            https://slack.com/api/chat.postMessage