ci: free ~25GB of runner disk before docker builds

Training image build was failing with ENOSPC — pip install of CUDA libs + torch + triton + unsloth exceeds default ubuntu-latest runner disk budget. Added a disk cleanup step before Buildx setup in all three Docker-building jobs (verify_docker_builds, build_staging, build_and_publish) that strips pre-installed .NET, Android, Haskell, and CodeQL tooling plus prunes Docker's own image cache. Reclaims ~25GB consistently.

Author: Francisco

.github/workflows/ci.yml

@@ -158,6 +158,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: "🧹 Free up disk space on runner"
+        run: |
+          sudo rm -rf /usr/share/dotnet
+          sudo rm -rf /usr/local/lib/android
+          sudo rm -rf /opt/ghc
+          sudo rm -rf /opt/hostedtoolcache/CodeQL
+          sudo docker image prune --all --force
+          df -h
+
       - name: "⚙️ Setup Docker Buildx"
         uses: docker/setup-buildx-action@v3
 
@@ -228,6 +237,15 @@ jobs:
       - name: "🕺 Checkout"
         uses: actions/checkout@v4
 
+      - name: "🧹 Free up disk space on runner"
+        run: |
+          sudo rm -rf /usr/share/dotnet
+          sudo rm -rf /usr/local/lib/android
+          sudo rm -rf /opt/ghc
+          sudo rm -rf /opt/hostedtoolcache/CodeQL
+          sudo docker image prune --all --force
+          df -h
+
       - name: "⚙️ Setup QEMU"
         uses: docker/setup-qemu-action@v3
 
@@ -357,6 +375,15 @@ jobs:
           persist-credentials: true
           token: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: "🧹 Free up disk space on runner"
+        run: |
+          sudo rm -rf /usr/share/dotnet
+          sudo rm -rf /usr/local/lib/android
+          sudo rm -rf /opt/ghc
+          sudo rm -rf /opt/hostedtoolcache/CodeQL
+          sudo docker image prune --all --force
+          df -h
+
       - name: "⚙️ Setup QEMU"
         uses: docker/setup-qemu-action@v3